| X | ||||||||||
- Definition If the value is true, then the document is an amendment to previously-filed/accepted document. No definition available.
|
| X | ||||||||||
- Definition End date of current fiscal year in the format --MM-DD. No definition available.
|
| X | ||||||||||
- Definition This is focus fiscal period of the document report. For a first quarter 2006 quarterly report, which may also provide financial information from prior periods, the first fiscal quarter should be given as the fiscal period focus. Values: FY, Q1, Q2, Q3, Q4, H1, H2, M9, T1, T2, T3, M8, CY. No definition available.
|
| X | ||||||||||
- Definition This is focus fiscal year of the document report in CCYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006. No definition available.
|
| X | ||||||||||
- Definition The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD. No definition available.
|
| X | ||||||||||
- Definition The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word "Other". No definition available.
|
| X | ||||||||||
- Definition A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Indicate number of shares or other units outstanding of each of registrant's classes of capital or common stock or other ownership interests, if and as stated on cover of related periodic report. Where multiple classes or units exist define each class/interest by adding class of stock items such as Common Class A [Member], Common Class B [Member] or Partnership Interest [Member] onto the Instrument [Domain] of the Entity Listings, Instrument. No definition available.
|
| X | ||||||||||
- Definition Indicate "Yes" or "No" whether registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. This information should be based on the registrant's current or most recent filing containing the related disclosure. No definition available.
|
| X | ||||||||||
- Definition Indicate whether the registrant is one of the following: (1) Large Accelerated Filer, (2) Accelerated Filer, (3) Non-accelerated Filer, (4) Smaller Reporting Company (Non-accelerated) or (5) Smaller Reporting Accelerated Filer. Definitions of these categories are stated in Rule 12b-2 of the Exchange Act. This information should be based on the registrant's current or most recent filing containing the related disclosure. No definition available.
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition State aggregate market value of voting and non-voting common equity held by non-affiliates computed by reference to price at which the common equity was last sold, or average bid and asked price of such common equity, as of the last business day of registrant's most recently completed second fiscal quarter. The public float should be reported on the cover page of the registrants form 10K. No definition available.
|
| X | ||||||||||
- Definition The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
CONDENSED STATEMENTS OF CONSOLIDATED INCOME (Unaudited) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
||||||
| Revenues: | |||||||||
| Utility revenues | $ 1,299 | $ 1,233 | $ 4,534 | $ 4,001 | |||||
| Non-utility revenues | 913 | 865 | 3,019 | 2,975 | |||||
| Total | 2,212 | 2,098 | 7,553 | 6,976 | |||||
| Expenses: | |||||||||
| Utility natural gas | 134 | 106 | 959 | 706 | |||||
| Cost of Goods and Services Sold | [1] | 864 | 832 | 2,927 | 2,843 | ||||
| Operation and maintenance | 567 | 501 | 1,714 | 1,562 | |||||
| Depreciation and amortization | 326 | 269 | 982 | 749 | |||||
| Taxes other than income taxes | 95 | 93 | 307 | 288 | |||||
| Total | 1,986 | 1,801 | 6,889 | 6,148 | |||||
| Operating Income (Loss) | 226 | 297 | 664 | 828 | |||||
| Other Income (Expense): | |||||||||
| Gain on marketable securities | 43 | 37 | 66 | 104 | |||||
| Loss on indexed debt securities | (44) | (36) | (316) | (59) | |||||
| Interest and other finance charges | (90) | (80) | (259) | (235) | |||||
| Interest on Securitization Bonds | (16) | (18) | (46) | (58) | |||||
| Equity in earnings of unconsolidated affiliate, net | 81 | 68 | 208 | 199 | |||||
| Other, net | 9 | (1) | 16 | (2) | |||||
| Total | (17) | (30) | (331) | (51) | |||||
| Income (Loss) Before Income Taxes | 209 | 267 | 333 | 777 | |||||
| Income tax expense (benefit) | 51 | 98 | 85 | 281 | |||||
| Net Income | 158 | 169 | 248 | 496 | |||||
| Series A Preferred Stock dividend requirement | 5 | 0 | 5 | 0 | |||||
| Income Available to Common Shareholders | $ 153 | $ 169 | $ 243 | $ 496 | |||||
| Basic Earnings Per Common Share | $ 0.35 | $ 0.39 | $ 0.56 | $ 1.15 | |||||
| Diluted Earnings Per Common Share | 0.35 | 0.39 | 0.56 | 1.14 | |||||
| Dividends Declared Per Share | $ 0.2775 | $ 0.2675 | $ 0.5550 | [2] | $ 0.8025 | ||||
| Weighted Average Common Shares Outstanding, Basic | 431,554,000 | 431,026,000 | 431,437,000 | 430,939,000 | |||||
| Weighted Average Common Shares Outstanding, Diluted | 434,891,000 | 434,086,000 | 434,774,000 | 433,999,000 | |||||
| Houston Electric [Member] | |||||||||
| Revenues: | |||||||||
| Total | $ 897 | $ 843 | $ 2,506 | $ 2,233 | |||||
| Expenses: | |||||||||
| Operation and maintenance | 369 | 337 | 1,062 | 1,021 | |||||
| Depreciation and amortization | 242 | 193 | 737 | 525 | |||||
| Taxes other than income taxes | 59 | 59 | 180 | 177 | |||||
| Total | 670 | 589 | 1,979 | 1,723 | |||||
| Operating Income (Loss) | 227 | 254 | 527 | 510 | |||||
| Other Income (Expense): | |||||||||
| Interest and other finance charges | (32) | (32) | (101) | (97) | |||||
| Interest on Securitization Bonds | (16) | (18) | (46) | (58) | |||||
| Other, net | 0 | (3) | (6) | (9) | |||||
| Total | (48) | (53) | (153) | (164) | |||||
| Income (Loss) Before Income Taxes | 179 | 201 | 374 | 346 | |||||
| Income tax expense (benefit) | 36 | 71 | 78 | 123 | |||||
| Net Income | 143 | 130 | 296 | 223 | |||||
| CERC Corp [Member] | |||||||||
| Revenues: | |||||||||
| Utility revenues | 402 | 390 | 2,032 | 1,767 | |||||
| Non-utility revenues | 910 | 861 | 3,008 | 2,964 | |||||
| Total | 1,312 | 1,251 | 5,040 | 4,731 | |||||
| Expenses: | |||||||||
| Utility natural gas | 134 | 106 | 959 | 706 | |||||
| Cost of Goods and Services Sold | 864 | 832 | 2,927 | 2,843 | |||||
| Operation and maintenance | 211 | 182 | 666 | 587 | |||||
| Depreciation and amortization | 77 | 68 | 222 | 202 | |||||
| Taxes other than income taxes | 33 | 32 | 120 | 104 | |||||
| Total | 1,319 | 1,220 | 4,894 | 4,442 | |||||
| Operating Income (Loss) | (7) | 31 | 146 | 289 | |||||
| Other Income (Expense): | |||||||||
| Interest and other finance charges | (30) | (32) | (92) | (92) | |||||
| Other, net | 0 | (4) | (5) | (13) | |||||
| Total | (30) | (36) | (97) | (105) | |||||
| Income (Loss) Before Income Taxes | (37) | (5) | 49 | 184 | |||||
| Income tax expense (benefit) | (2) | (1) | 14 | 69 | |||||
| Income (Loss) From Continuing Operations | (35) | (4) | 35 | 115 | |||||
| Income from discontinued operations (net of tax of $13, $26, $44 and $75, respectively) | 44 | 42 | 140 | 124 | |||||
| Net Income | $ 9 | $ 38 | $ 175 | $ 239 | |||||
| |||||||||
| X | ||||||||||
- Definition This item represents the net total realized and unrealized gain (loss) included in earnings for the period related to indexed debt securities. No definition available.
|
| X | ||||||||||
- Definition Interest and debt related expenses associated with transition and system restoration bonds. No definition available.
|
| X | ||||||||||
- Definition Aggregate dividends declared during the period for each share of common stock outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Total costs of sales and operating expenses for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount after tax of income (loss) from continuing operations attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount after tax of income (loss) from a discontinued operation attributable to the parent. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Interest and debt related expenses associated with nonoperating financing activities of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition The net result for the period of deducting operating expenses from operating revenues. No definition available.
|
| X | ||||||||||
- Definition Amount of income (expense) related to nonoperating activities, classified as other. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The aggregate value of preferred stock dividends and other adjustments necessary to derive net income apportioned to common stockholders. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The total amount of regulated operating revenues recognized during the period. No definition available.
|
| X | ||||||||||
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere. These taxes could include production, real estate, personal property, and pump tax. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The amount of unregulated operating revenues recognized during the period. No definition available.
|
| X | ||||||||||
- Definition Amount of operating expense for purchased gas and petroleum of regulated operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The amount of operating expenses for the period that are associated with the utility's normal revenue producing operation; including selling, general, and administrative expenses, costs incurred for routine plant repairs and maintenance, and operations. No definition available.
|
| X | ||||||||||
- Definition The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
CONDENSED STATEMENTS OF CONSOLIDATED INCOME (Parentheticals) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
|
| CERC Corp [Member] | ||||
| Income tax expense associated with discontinued operations | $ 13 | $ 26 | $ 44 | $ 75 |
| X | ||||||||||
- Definition Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|
CONDENSED STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
|
| Net income | $ 158 | $ 169 | $ 248 | $ 496 |
| Other comprehensive income (loss): | ||||
| Adjustment to pension and other postretirement plans (net of tax of $1, $2, $2 and $4) | 1 | 0 | 4 | 2 |
| Net deferred gain (loss) from cash flow hedges (net of tax) | 3 | (2) | 6 | (3) |
| Total | 4 | (2) | 10 | (1) |
| Comprehensive income | 162 | 167 | 258 | 495 |
| Houston Electric [Member] | ||||
| Net income | 143 | 130 | 296 | 223 |
| Other comprehensive income (loss): | ||||
| Net deferred gain (loss) from cash flow hedges (net of tax) | 3 | 0 | 7 | (1) |
| Total | 3 | 0 | 7 | (1) |
| Comprehensive income | 146 | 130 | 303 | 222 |
| CERC Corp [Member] | ||||
| Net income | 9 | 38 | 175 | 239 |
| Other comprehensive income (loss): | ||||
| Net deferred gain (loss) from cash flow hedges (net of tax) | 0 | (1) | 0 | (1) |
| Comprehensive income | $ 9 | $ 38 | $ 175 | $ 239 |
| X | ||||||||||
- Definition Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan, attributable to parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount after tax of other comprehensive income (loss) attributable to parent entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
CONDENSED STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME (Parentheticals) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
|
| Tax benefit (expense) on adjustment related to pension and postretirement plans | $ (1) | $ (2) | $ (2) | $ (4) |
| Tax expense (benefit) on net deferred gain (loss) from cash flow hedges | 1 | (2) | 2 | (2) |
| Houston Electric [Member] | ||||
| Tax expense (benefit) on net deferred gain (loss) from cash flow hedges | $ 1 | $ 0 | $ 2 | $ 0 |
| X | ||||||||||
- Definition Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income for defined benefit plan, attributable to parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of tax expense (benefit), after reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Definition Sum of the carrying amounts as of the balance sheet date of assets that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer, excluding property, plant and equipment. No definition available.
|
| X | ||||||||||
- Definition AssetsNoncurrentOtherThanPropertyPlantAndEquipment [Abstract] No definition available.
|
| X | ||||||||||
- Definition Represents the caption on the face of the balance sheet represent total cumulative preferred stock presented in detail within the Shareholder's Equity section. No definition available.
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Long-term transition and system restoration bonds are securitization bonds issued to recover qualified stranded costs and qualified storm recovery costs. This represents the current portion. No definition available.
|
| X | ||||||||||
- Definition Carrying value as of the balance sheet date of transition and system restoration bond debt (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. No definition available.
|
| X | ||||||||||
- Definition Carrying amount as of the balance sheet date, net of allowance for doubtful accounts, of account and note receivables due from other than related parties. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount classified as assets attributable to disposal group held for sale or disposed of. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Represents the caption on the face of the balance sheet to indicate that the entity has entered into (1) purchase or supply arrangements that will require expending a portion of its resources to meet the terms thereof, and (2) is exposed to potential losses or, less frequently, gains, arising from (a) possible claims against a company's resources due to future performance under contract terms, and (b) possible losses or likely gains from uncertainties that will ultimately be resolved when one or more future events that are deemed likely to occur do occur or fail to occur. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The current portion of money or property received from customers which is either to be returned upon satisfactory contract completion or applied to customer receivables in accordance with the terms of the contract or the understandings. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences, with jurisdictional netting and classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount classified as deferred tax liabilities attributable to disposal group held for sale or disposed of. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The aggregate amount of receivables to be collected from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth, at the financial statement date. which are usually due within one year (or one business cycle). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Carrying amount as of the balance sheet date of natural gas in storage, which is a mixture of gases (liquefied or otherwise), used for fuel and manufacturing purposes, which is ready for sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Carrying amount due within one year of the balance sheet date (or one operating cycle, if longer) from tax authorities as of the balance sheet date representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Gross amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of liabilities and equity items, including the portion of equity attributable to noncontrolling interests, if any. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Aggregated carrying amounts of obligations as of the balance sheet date, excluding long-term debt, incurred as part of the normal operations that are expected to be paid after one year or beyond the normal operating cycle, if longer. Alternate captions include Total Deferred Credits and Other Liabilities. No definition available.
|
| X | ||||||||||
- Definition Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of investments in debt and equity securities, including, but not limited to, held-to-maturity, trading and available-for-sale expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of noncurrent assets classified as other. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of liabilities classified as other, due within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of long-term debt classified as other, payable within one year or the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of long-term debt classified as other, payable after one year or the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Aggregate par or stated value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The period end amount for a type of inventory held by the utility in a schedule of inventories. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The cumulative amount of the reporting entity's undistributed earnings or deficit. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Carrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, use, payroll, excise, real, property and other taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount received for services rendered and products shipped, but not yet billed, for non-contractual agreements due within one year or the normal operating cycle, if longer. No definition available.
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Definition Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Face amount or stated value per share of common stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Value of the difference between preference in liquidation and the par or stated values of the preferred shares. No definition available.
|
| X | ||||||||||
- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Definition This represents a distribution to ZENS holders during the period in accordance with the terms of the ZENS. No definition available.
|
| X | ||||||||||
- Definition The increase (decrease) in net accounts receivables and payables due to/from affiliates. No definition available.
|
| X | ||||||||||
- Definition Increase (decrease) in interest and taxes accrued. No definition available.
|
| X | ||||||||||
- Definition This item represents the net total realized and unrealized gain (loss) included in earnings for the period related to indexed debt securities. No definition available.
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of amortization expense attributable to debt issuance costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of increase (decrease) in cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; excluding effect from exchange rate change. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash inflow (outflow) of financing activities of discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash inflow (outflow) of investing activities of discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash inflow (outflow) of operating activities of discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount after tax of income (loss) from continuing operations attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount after tax of income (loss) from a discontinued operation attributable to the parent. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition This element represents the undistributed income (or loss) of equity method investments, net of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporations; such investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The increase (decrease) during the reporting period in the amount due from customers for the credit sale of goods and services; includes accounts receivable and other types of receivables. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The increase (decrease) during the reporting period in the aggregate amount of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The increase (decrease) during the period in the net carrying value of derivative instruments reported as assets and liabilities that are due to be disposed of within one year (or the normal operating cycle, if longer). No definition available.
|
| X | ||||||||||
- Definition The increase (decrease) during the reporting period in income taxes receivable, which represents the amount due from tax authorities for refunds of overpayments or recoveries of income taxes paid. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The increase (decrease) during the reporting period in money or securities placed with a broker or counterparty as security for a trading or derivative position. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The increase (decrease) during the reporting period in the amount owed by the reporting entry in the form of loans and obligations (generally evidenced by promissory notes) made by the following types of related parties: a parent company and its subsidiaries; subsidiaries of a common parent; an entity and trust for the benefit of employees, such as pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management, an entity and its principal owners, management, or member of their immediate families, affiliates, or other parties with the ability to exert significant influence. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The increase (decrease) during the reporting period in the amount owed to the reporting entity in the form of loans and obligations (generally evidenced by promissory notes) made to the following types of related parties: a parent company and its subsidiaries; subsidiaries of a common parent; an entity and trust for the benefit of employees, such as pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management, an entity and its principal owners, management, or member of their immediate families, affiliates, or other parties with the ability to exert significant influence. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of increase (decrease) in current assets classified as other. No definition available.
|
| X | ||||||||||
- Definition Amount of increase (decrease) in current liabilities classified as other. No definition available.
|
| X | ||||||||||
- Definition Amount of increase (decrease) in noncurrent assets classified as other. No definition available.
|
| X | ||||||||||
- Definition Amount of increase (decrease) in noncurrent operating liabilities classified as other. No definition available.
|
| X | ||||||||||
- Definition The increase (decrease) during the reporting period in the value of the asset or liability created by an over or under recovery. An over under-recovery means that the basic energy price based on the daily product price and exchange rate is less (over) or more (under) than the basic energy price used in the calculation of the monthly retail energy product. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The increase (decrease) during the reporting period in the value of assets that are created when regulatory agencies permits public utilities to defer costs (revenues) to the balance sheet. This element is a the increase (decrease) of regulatory assets and liabilities combined. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition This item represents the total unrealized gain (loss) included in earnings for the period as a result of holding marketable securities categorized as trading, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash inflow (outflow) of financing activities, excluding discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash inflow (outflow) of investing activities, excluding discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash inflow (outflow) from operating activities, excluding discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Other cash or noncash adjustments to reconcile net income to cash provided by (used in) operating activities that are not separately disclosed in the statement of cash flows (for example, cash received or cash paid during the current period for miscellaneous operating activities, net change during the reporting period in other assets or other liabilities). No definition available.
|
| X | ||||||||||
- Definition Amount of cash (inflow) outflow from investing activities classified as other. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of payment for pension benefits. Excludes other postretirement benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The cash inflow from parent as a source of financing that is recorded as additional paid in capital. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of distribution received from equity method investee for return of investment, classified as investing activities. Excludes distribution for return on investment, classified as operating activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Proceeds from issuance of capital stock which provides for a specific dividend that is paid to the shareholders before any dividends to common stockholders and which takes precedence over common stockholders in the event of liquidation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of cash inflow (outflow) from financing activities classified as other. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The net cash inflow or cash outflow from issuing (borrowing) and repaying commercial paper. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The net cash inflow or outflow for borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The cash inflow associated with the aggregate amount received by the entity through sale or maturity of marketable securities (held-to-maturity or available-for-sale) during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Background and Basis of Presentation |
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Sep. 30, 2018 | |||||||||
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | |||||||||
| Background and Basis of Presentation [Text Block] | Background and Basis of Presentation No Registrant makes any representations as to the information related solely to CenterPoint Energy or the subsidiaries of CenterPoint Energy other than itself. General. Included in this combined Form 10-Q are the Interim Condensed Financial Statements of CenterPoint Energy, Houston Electric and CERC, which are referred to collectively as the Registrants. The Combined Notes to the Unaudited Condensed Consolidated Financial Statements apply to all Registrants unless otherwise indicated. The Interim Condensed Financial Statements are unaudited, omit certain financial statement disclosures and should be read with each of the Registrants’ 2017 Form 10-K. Background. CenterPoint Energy, Inc. is a public utility holding company and owns interests in Enable as described below. CenterPoint Energy’s operating subsidiaries, Houston Electric and CERC, own and operate electric transmission and distribution and natural gas distribution facilities and supply natural gas to commercial and industrial customers and electric and natural gas utilities.
As of September 30, 2018, CenterPoint Energy, indirectly through CNP Midstream, owned approximately 54.0% of the common units representing limited partner interests in Enable, 50% of the management rights and 40% of the incentive distribution rights in Enable GP and also directly owned an aggregate of 14,520,000 Enable Series A Preferred Units. Enable owns, operates and develops natural gas and crude oil infrastructure assets. On September 4, 2018, CERC entered into a Contribution Agreement, by and between CERC and CNP Midstream, a new subsidiary formed by CERC in June 2018, pursuant to which CERC contributed its equity investment in Enable consisting of Enable common units and its interests in Enable GP, to CNP Midstream (collectively, the Enable Contribution). Immediately following the Enable Contribution, CERC distributed all of its interest in CNP Midstream to Utility Holding, CERC’s sole stockholder and a wholly-owned subsidiary of CenterPoint Energy. Utility Holding then distributed all of its interest in CNP Midstream to CenterPoint Energy, its sole member (collectively with the Enable Contribution, the Internal Spin). CERC executed the Internal Spin to, among other things, enhance the access of CERC and CenterPoint Energy to low cost debt and equity through increased transparency and understandability of the financial statements, improve CERC’s credit quality by eliminating the exposure to Enable’s midstream business and provide clarity of internal reporting and performance metrics to enhance management’s decision making for CERC and CNP Midstream. As a result of the Internal Spin, CERC’s equity in earnings in Enable and related income taxes have been classified as discontinued operations in CERC’s Interim Condensed Financial Statements. For further information regarding the Internal Spin and CERC’s presentation of discontinued operations, see Note 9. As of September 30, 2018, CenterPoint Energy and Houston Electric had VIEs consisting of the Bond Companies, which are consolidated. The consolidated VIEs are wholly-owned, bankruptcy-remote, special purpose entities that were formed specifically for the purpose of securitizing transition and system restoration-related property. Creditors of CenterPoint Energy and Houston Electric have no recourse to any assets or revenues of the Bond Companies. The bonds issued by these VIEs are only payable from and secured by transition and system restoration property, and the bondholders have no recourse to the general credit of CenterPoint Energy or Houston Electric. Basis of Presentation. The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. The Interim Condensed Financial Statements reflect all normal recurring adjustments that are, in the opinion of management, necessary to present fairly the financial position, results of operations and cash flows for the respective periods. Amounts reported in the Condensed Statements of Consolidated Income are not necessarily indicative of amounts expected for a full-year period due to the effects of, among other things, (a) seasonal fluctuations in demand for energy and energy services, (b) changes in energy commodity prices, (c) timing of maintenance and other expenditures and (d) acquisitions and dispositions of businesses, assets and other interests. Certain prior year amounts have been reclassified to conform to the current year presentation. See Notes 2 and 9 for further discussion. For a description of the Registrants’ reportable business segments, see Note 16. |
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- References No definition available.
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- Definition The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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New Accounting Pronouncements |
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| New Accounting Pronouncements and Changes in Accounting Principles [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| New Accounting Pronouncements [Text Block] | New Accounting Pronouncements The following table provides an overview of recently adopted or issued accounting pronouncements applicable to all the Registrants, unless otherwise noted.
The table below reflects the impact of adoption of ASU 2017-07:
Management believes that other recently adopted standards and recently issued standards that are not yet effective will not have a material impact on the Registrants’ financial position, results of operations or cash flows upon adoption. |
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- Definition The entire disclosure for a new accounting pronouncement that has been issued but not yet adopted. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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Pending Merger with Vectren (CenterPoint Energy) |
9 Months Ended |
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Sep. 30, 2018 | |
| Business Combinations [Abstract] | |
| Pending Merger with Vectren (CenterPoint Energy) [Text Block] | Pending Merger with Vectren (CenterPoint Energy) On April 21, 2018, CenterPoint Energy entered into the Merger Agreement. Under the terms of the Merger Agreement, CenterPoint Energy will acquire Vectren for approximately $6 billion in cash. Upon closing, Vectren will become a wholly-owned subsidiary of CenterPoint Energy. Pursuant to the Merger Agreement, upon the closing of the Merger, each share of Vectren common stock issued and outstanding immediately prior to the closing will be converted automatically into the right to receive $72.00 in cash per share. During August and October 2018, CenterPoint Energy completed its permanent financing for the Merger through offerings of the Series A Preferred Stock, depositary shares, each representing a 1/20th interest in a share of Series B Preferred Stock, Common Stock and unsecured senior notes. See Notes 12 and 19 for further details regarding the Merger financings. As of September 30, 2018, Vectren and its subsidiaries had outstanding $325 million of short-term debt and $2.0 billion of long-term debt, including current maturities. It is anticipated that Vectren and its subsidiaries will have approximately $2.5 billion of outstanding short-term and long-term debt as of December 31, 2018. Consummation of the Merger is conditioned upon approval by federal regulatory commissions, orders from state regulatory commissions, expiration or termination of the applicable HSR waiting period and approval of the Merger by Vectren shareholders. In June 2018, CenterPoint Energy and Vectren (i) submitted their filings with the FERC and the FCC, (ii) submitted their filings with the FTC pursuant to the HSR Act and (iii) initiated informational proceedings with regulators in Indiana and Ohio. On June 26, 2018, CenterPoint Energy and Vectren received notice from the FTC granting early termination of the waiting period under the HSR Act in connection with the Merger. On August 28, 2018, shareholders of Vectren, during a special shareholders’ meeting, approved the Merger. The FCC granted approvals on July 20 and 24, 2018, and on October 5, 2018, the FERC authorized the Merger. A hearing before the Indiana Utility Regulatory Commission was held on October 17, 2018 with respect to the Merger. CenterPoint Energy has requested a final order for this proceeding by the end of January or early February 2019. The Merger Agreement contains termination rights for both CenterPoint Energy and Vectren, and provides that, upon termination of the Merger Agreement under specified circumstances, CenterPoint Energy would be required to pay a termination fee of $210 million to Vectren or Vectren would be required to pay CenterPoint Energy a termination fee of $150 million. Subject to receipt of required regulatory and statutory approvals and satisfaction and/or waiver of the closing conditions, CenterPoint Energy continues to anticipate closing the Merger in the first quarter of 2019. |
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- Definition The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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Revenue Recognition |
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| Revenue from Contract with Customer [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Revenue Recognition [Text Block] | Revenue Recognition The Registrants adopted ASC 606 and all related amendments on January 1, 2018 using the modified retrospective method for those contracts that were not completed as of the date of adoption. Application of the new revenue standard did not result in a cumulative effect adjustment to the opening balance of retained earnings. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. The adoption of the new standard did not have a material impact on the Registrants’ financial position, results of operations or cash flows. In accordance with ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration to which the Registrants expect to be entitled to receive in exchange for these goods or services. Contract assets and liabilities are not material. The following tables disaggregate revenues by reportable business segment and major source: CenterPoint Energy
Houston Electric
CERC
Revenues from Contracts with Customers Electric Transmission & Distribution. Houston Electric distributes electricity to customers over time and customers consume the electricity when delivered. Revenue, consisting of both volumetric and fixed tariff rates set by the PUCT, is recognized as electricity is delivered and represents amounts both billed and unbilled. Discretionary services requested by customers are provided at a point in time with control transferring upon the completion of the service. Revenue for discretionary services is recognized upon completion of service based on the tariff rates set by the PUCT. Payments for electricity distribution and discretionary services are aggregated and received on a monthly basis. Houston Electric performs transmission services over time as a stand-ready obligation to provide a reliable network of transmission systems. Revenue is recognized upon time elapsed, and the monthly tariff rate set by the PUCT. Payments are received on a monthly basis. Natural Gas Distribution. CERC distributes and transports natural gas to customers over time, and customers consume the natural gas when delivered. Revenue, consisting of both volumetric and fixed tariff rates set by the state governing agency for that service area, is recognized as natural gas is delivered and represents amounts both billed and unbilled. Discretionary services requested by the customer are satisfied at a point in time and revenue is recognized upon completion of service and the tariff rates set by the applicable state regulator. Payments of natural gas distribution, transportation and discretionary services are aggregated and received on a monthly basis. Energy Services. The majority of CES natural gas sales contracts are considered a derivative, as the contracts typically have a stated minimum or contractual volume of delivery. For contracts in which CES delivers the full requirement of the natural gas needed by the customer and a volume is not stated, a contract as defined under ASC 606 is created upon the customer’s exercise of its option to take natural gas. CES supplies natural gas to retail customers over time as customers consume the natural gas when delivered. For wholesale customers, CES supplies natural gas at a point in time because the wholesale customer is presumed to have storage capabilities. Control is transferred to both types of customers upon delivery of natural gas. Revenue is recognized on a monthly basis based on the estimated volume of natural gas delivered and the price agreed upon with the customer. Payments are received on a monthly basis. AMAs are natural gas sales contracts under which CES also assumes management of a customer’s physical storage and/or transportation capacity. AMAs have two distinct performance obligations, which consist of natural gas sales and natural gas delivery because delivery could occur separate from the sale of natural gas (e.g., from storage to customer premises). Most AMAs’ natural gas sales performance obligations are accounted for as embedded derivatives. The transaction price is allocated between the sale of natural gas and the delivery based on the stand-alone selling price as stated in the contract. CES performs natural gas delivery over time as customers take delivery of the natural gas and recognizes revenue on an aggregated monthly basis based on the volume of natural gas delivered and the fees stated within the contract. Payments are received on a monthly basis. Practical Expedients and Exemption. Sales taxes and other similar taxes collected from customers are excluded from the transaction price. |
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- References No definition available.
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- Definition The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Employee Benefit Plans |
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| Retirement Benefits [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Employee Benefit Plans [Text Block] | Employee Benefit Plans The Registrants’ net periodic cost, before considering amounts subject to overhead allocations for capital expenditure projects or for amounts subject to deferral for regulatory purposes, includes the following components relating to pension and postretirement benefits: Pension Benefits (CenterPoint Energy)
Postretirement Benefits
Changes in accumulated other comprehensive loss related to defined benefit and postretirement plans are as follows: CenterPoint Energy
The table below reflects the expected contributions to be made to the pension plans and postretirement benefit plan during 2018:
The table below reflects the contributions made to the pension plans and postretirement benefit plan during 2018:
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- References No definition available.
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- Definition The entire disclosure for pension and other postretirement benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Regulatory Accounting |
9 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Regulatory Assets and Liabilities, Other Disclosures [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Regulatory Accounting [Text Block] | Regulatory Accounting The following is a list of regulatory assets and liabilities reflected on the Registrants’ Condensed Consolidated Balance Sheets:
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- Definition The entire disclosure for public utilities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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Derivative Instruments |
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| Derivative Instruments and Hedging Activities Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Derivative Instruments [Text Block] | Derivative Instruments The Registrants are exposed to various market risks. These risks arise from transactions entered into in the normal course of business. The Registrants utilize derivative instruments such as physical forward contracts, swaps and options to mitigate the impact of changes in commodity prices, weather and interest rates on its operating results and cash flows. Such derivatives are recognized in the Registrants’ Condensed Consolidated Balance Sheets at their fair value unless the Registrants elect the normal purchase and sales exemption for qualified physical transactions. A derivative may be designated as a normal purchase or normal sale if the intent is to physically receive or deliver the product for use or sale in the normal course of business. CenterPoint Energy has a Risk Oversight Committee composed of corporate and business segment officers that oversees commodity price, weather and credit risk activities, including the Registrants’ marketing, risk management services and hedging activities. The committee’s duties are to establish the Registrants’ commodity risk policies, allocate board-approved commercial risk limits, approve the use of new products and commodities, monitor positions and ensure compliance with the Registrants’ commercial risk management policy and procedures and limits established by CenterPoint Energy’s Board of Directors. The Registrants’ policies prohibit the use of leveraged financial instruments. A leveraged financial instrument, for this purpose, is a transaction involving a derivative whose financial impact will be based on an amount other than the notional amount or volume of the instrument.
Commodity Derivative Instruments. CenterPoint Energy and CERC, through CES, enter into certain derivative instruments to mitigate the effects of commodity price movements. Certain financial instruments used to hedge portions of the natural gas inventory of the Energy Services business segment are designated as fair value hedges for accounting purposes. All other financial instruments do not qualify or are not designated as cash flow or fair value hedges. Weather Hedges. CenterPoint Energy and CERC have weather normalization or other rate mechanisms that mitigate the impact of weather on NGD in Arkansas, Louisiana, Mississippi, Minnesota and Oklahoma. NGD and electric operations in Texas do not have such mechanisms, although fixed customer charges are historically higher in Texas for NGD compared to its other jurisdictions. As a result, fluctuations from normal weather may have a positive or negative effect on NGD’s results in Texas and on electric operations’ results in its service territory. CenterPoint Energy and CERC, as applicable, enter into winter season weather hedges from time to time for certain NGD jurisdictions and electric operations’ service territory to mitigate the effect of fluctuations from normal weather on results of operations and cash flows. These weather hedges are based on heating degree days at 10-year normal weather. Houston Electric does not enter into weather hedges. The table below summarizes CenterPoint Energy’s and CERC’s current weather hedge gain (loss) activity:
Cash Flow Hedging of Interest Expense. From time to time, the Registrants enter into forward interest rate agreements with certain counterparties designated as cash flow hedges. The objective of these cash flow hedges is to reduce exposure to variability in cash flows related to interest payments on anticipated future fixed rate debt offerings or other exposure to variable rate debt. In October 2018, Houston Electric entered into an additional $100 million of notional amount on forward interest rate agreements classified as cash flow hedges. As of September 30, 2018 and December 31, 2017, the total outstanding notional amount of Houston Electric’s forward interest rate agreements related to cash flow hedges was $100 million and $-0-, respectively. The maximum length of time over which Houston Electric is exposed to the variability in future cash flows of the forecasted debt offerings is less than 12 months. Economic Hedging of Interest Rate Risk. From time to time, the Registrants may enter into forward interest rate agreements with certain counterparties designated as economic hedges. The objective of these economic hedges is to offset any interest rate risk borne by one or more of the Registrants in connection with an anticipated future fixed rate debt offering or other exposure to variable rate debt. As of September 30, 2018 and December 31, 2017, the total outstanding notional amount of CenterPoint Energy’s forward interest rate agreements related to economic hedges in connection with the permanent financing for the Merger was $200 million and $-0-, respectively. As of September 30, 2018 and December 31, 2017, the fair value of interest rate derivatives was less than $1 million and therefore was not included in the tabular presentation below.
The following tables present information about derivative instruments and hedging activities. The first two tables provide a balance sheet overview of Derivative Assets and Liabilities, while the last table provides a breakdown of the related income statement impacts. Fair Value of Derivative Instruments and Hedged Items
Cumulative Basis Adjustment for Fair Value Hedges (CenterPoint Energy and CERC)
Offsetting of Natural Gas Derivative Assets and Liabilities (CenterPoint Energy and CERC)
Income Statement Impact of Hedge Accounting Activity (CenterPoint Energy and CERC)
Effect of Cash Flow Hedge Accounting on Accumulated Other Comprehensive Income
CenterPoint Energy and CERC enter into financial derivative contracts containing material adverse change provisions. These provisions could require CenterPoint Energy or CERC to post additional collateral if the S&P or Moody’s credit ratings of CenterPoint Energy, Inc. or its subsidiaries, including CERC Corp., are downgraded. CenterPoint Energy and CERC
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- Definition The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| Fair Value Disclosures [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Fair Value Measurements [Text Block] | Fair Value Measurements Assets and liabilities that are recorded at fair value in the Registrants’ Condensed Consolidated Balance Sheets are categorized based upon the level of judgment associated with the inputs used to measure their value. Hierarchical levels, as defined below and directly related to the amount of subjectivity associated with the inputs to fair valuations of these assets and liabilities, are as follows: Level 1: Inputs are unadjusted quoted prices in active markets for identical assets or liabilities at the measurement date. The types of assets carried at Level 1 fair value generally are exchange-traded derivatives and equity securities, as well as natural gas inventory that has been designated as the hedged item in a fair value hedge. Level 2: Inputs, other than quoted prices included in Level 1, are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar instruments in active markets, and inputs other than quoted prices that are observable for the asset or liability. Fair value assets and liabilities that are generally included in this category are derivatives with fair values based on inputs from actively quoted markets. A market approach is utilized to value the Registrants’ Level 2 natural gas derivative assets or liabilities. CenterPoint Energy’s Level 2 indexed debt securities derivative is valued using an option model and a discounted cash flow model, which uses projected dividends on the ZENS-Related Securities and a discount rate as observable inputs. Level 3: Inputs are unobservable for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. Unobservable inputs reflect the Registrants’ judgments about the assumptions market participants would use in pricing the asset or liability since limited market data exists. The Registrants develop these inputs based on the best information available, including the Registrants’ own data. A market approach is utilized to value the Registrants’ Level 3 assets or liabilities. As of September 30, 2018, CenterPoint Energy’s and CERC’s Level 3 assets and liabilities are comprised of physical natural gas forward contracts and options. Level 3 physical natural gas forward contracts and options include illiquid forward price curve locations (ranging from $1.28 to $6.88 per MMBtu) as an unobservable input. CenterPoint Energy’s and CERC’s Level 3 physical natural gas forward contracts and options derivative assets and liabilities consist of both long and short positions (forwards and options). Forward price decreases (increases) as of September 30, 2018 would have resulted in lower (higher) values, respectively, for long forwards and options and higher (lower) values, respectively, for short forwards and options. The Registrants determine the appropriate level for each financial asset and liability on a quarterly basis. The Registrants also recognize purchases of Level 3 financial assets and liabilities at their fair market value at the end of the reporting period. The following tables present information about the Registrants’ assets and liabilities (including derivatives that are presented net) measured at fair value on a recurring basis and indicate the fair value hierarchy of the valuation techniques utilized by the Registrants to determine such fair value. CenterPoint Energy
Houston Electric
CERC
The following table presents additional information about assets or liabilities, including derivatives that are measured at fair value on a recurring basis for which CenterPoint Energy and CERC have utilized Level 3 inputs to determine fair value:
Estimated Fair Value of Financial Instruments The fair values of cash and cash equivalents, investments in debt and equity securities classified as “trading” and short-term borrowings are estimated to be approximately equivalent to carrying amounts and have been excluded from the table below. The carrying amounts of non-trading derivative assets and liabilities and CenterPoint Energy’s ZENS indexed debt securities derivative are stated at fair value and are excluded from the table below. The fair value of each debt instrument is determined by multiplying the principal amount of each debt instrument by a combination of historical trading prices and comparable issue data. These liabilities, which are not measured at fair value in the Registrants’ Condensed Consolidated Balance Sheets, but for which the fair value is disclosed, would be classified as Level 2 in the fair value hierarchy.
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Unconsolidated Affiliate (CenterPoint Energy and CERC) |
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| Equity Method Investments and Joint Ventures [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Unconsolidated Affiliate (CenterPoint Energy and CERC) [Text Block] | Unconsolidated Affiliate (CenterPoint Energy and CERC) CenterPoint Energy has the ability to significantly influence the operating and financial policies of Enable, a publicly traded MLP, and, accordingly, account for the investment in Enable’s common units using the equity method of accounting. Upon the adoption of ASU 2014-09 and ASU 2017-05 on January 1, 2018, CenterPoint Energy evaluated transactions in the investment in Enable that occurred prior to January 1, 2018 (the effective date) and concluded a cumulative effect adjustment to the opening balance of retained earnings was not required. See Note 2 for further discussion. CenterPoint Energy’s maximum exposure to loss related to Enable, a VIE in which CenterPoint Energy is not the primary beneficiary, is limited to the equity investment, the Series A Preferred Unit investment and outstanding current accounts receivable from Enable. On September 4, 2018, CERC completed the Internal Spin of its equity investment in Enable and Enable GP. The Internal Spin has been accounted for under the guidance for transactions between entities under common control. As of September 4, 2018, CERC derecognized its investment in Enable at carrying value on the date of distribution of $2.4 billion, net of deferred income taxes of $974 million, and CNP Midstream recorded the net asset contribution from CERC at CERC’s carrying value. Neither CERC nor CNP Midstream recognized a gain or loss upon the distribution or contribution, respectively, of net assets involved in the Internal Spin. In connection with the Internal Spin, CenterPoint Energy, through Utility Holding, made a $600 million capital contribution to CERC, which was used by CERC to repay outstanding indebtedness that historically supported CERC’s legacy midstream assets. See Note 18 for further discussion. Limited Partner Interest and Units Held in Enable (CenterPoint Energy):
Generally, sales to any person or entity (including a series of sales to the same person or entity) of more than 5% of the aggregate of the common units CNP Midstream owns in Enable or sales to any person or entity (including a series of sales to the same person or entity) by OGE of more than 5% of the aggregate of the common units it owns in Enable are subject to mutual rights of first offer and first refusal set forth in Enable’s Agreement of Limited Partnership. Interests Held in Enable GP (CenterPoint Energy):
Distributions Received from Enable (CenterPoint Energy and CERC):
Transactions with Enable (CenterPoint Energy and CERC):
Summarized unaudited consolidated income information for Enable is as follows:
Summarized unaudited consolidated balance sheet information for Enable is as follows:
Discontinued Operations (CERC): The Internal Spin represents a significant strategic shift that has a material effect on CERC’s operations and financial results and, as a result, CERC’s distribution of its equity investment in Enable met the criteria for discontinued operations classification. CERC has no continuing involvement in the equity investment of Enable. Therefore, CERC’s equity in earnings and related income taxes have been classified as Income from discontinued operations, net of tax, in CERC’s Condensed Statements of Consolidated Income for the periods presented. CERC’s equity method investment and related deferred income tax liabilities have been classified as Investment in unconsolidated affiliate - discontinued operations and Deferred income taxes, net - discontinued operations, respectively, in CERC’s Condensed Consolidated Balance Sheets for the periods presented. The following table presents amounts included in Income from discontinued operations, net of tax in CERC’s Condensed Statements of Consolidated Income.
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| X | ||||||||||
- References No definition available.
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- Definition The entire disclosure for equity method investments and joint ventures. Equity method investments are investments that give the investor the ability to exercise significant influence over the operating and financial policies of an investee. Joint ventures are entities owned and operated by a small group of businesses as a separate and specific business or project for the mutual benefit of the members of the group. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Goodwill and Other Intangibles (CenterPoint Energy and CERC) |
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| Goodwill and Intangible Assets Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Goodwill and Other Intangibles (CenterPoint Energy and CERC) [Text Block] | Goodwill and Other Intangibles (CenterPoint Energy and CERC) CenterPoint Energy’s and CERC’s goodwill by reportable business segment as of both September 30, 2018 and December 31, 2017 is as follows:
(1) Amount presented is net of the accumulated goodwill impairment charge of $252 million recorded in 2012. CenterPoint Energy and CERC perform goodwill impairment tests at least annually and evaluate goodwill when events or changes in circumstances indicate that its carrying value may not be recoverable. The impairment evaluation for goodwill is performed by comparing the fair value of each reporting unit with the carrying amount of the reporting unit, including goodwill. The estimated fair value of the reporting unit is primarily determined on the basis of discounted cash flows. If the carrying amount is in excess of the estimated fair value of the reporting unit, then the excess amount is the impairment charge that should be recorded, not to exceed the carrying amount of goodwill. See Note 2 for further discussion. CenterPoint Energy and CERC performed the annual goodwill impairment test in the third quarter of 2018 and determined that no goodwill impairment charge was required for any reporting unit, which approximate the reportable segments. The tables below present information on CenterPoint Energy’s and CERC’s other intangible assets recorded in Other non-current assets on the Condensed Consolidated Balance Sheets.
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- References No definition available.
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- Definition The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) |
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| Investments, Debt and Equity Securities [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) [Text Block] | Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) (a) Investment in Securities Related to ZENS In 1995, CenterPoint Energy sold a cable television subsidiary to TW and received certain TW securities as partial consideration. A subsidiary of CenterPoint Energy holds shares of certain securities detailed in the table below, which are classified as trading securities and are expected to be held to facilitate CenterPoint Energy’s ability to meet its obligation under the ZENS. Unrealized gains and losses resulting from changes in the market value of the ZENS-Related Securities are recorded in CenterPoint Energy’s Condensed Statements of Consolidated Income.
(b) ZENS In September 1999, CenterPoint Energy issued ZENS having an original principal amount of $1 billion of which $828 million remain outstanding as of September 30, 2018. Each ZENS was originally exchangeable at the holder’s option at any time for an amount of cash equal to 95% of the market value of the reference shares of TW Common attributable to such note. The number and identity of the reference shares attributable to each ZENS are adjusted for certain corporate events. On October 22, 2016, AT&T announced that it had entered into a definitive agreement to acquire TW in a stock and cash transaction. On February 15, 2017, TW shareholders approved the announced transaction with AT&T. The merger closed on June 14, 2018. CenterPoint Energy received $53.75 and 1.437 shares of AT&T Common for each share of TW Common held, resulting in cash proceeds of $382 million and 10,212,945 shares of AT&T Common. In accordance with the terms of the ZENS, CenterPoint Energy remitted $382 million to ZENS note holders in July 2018, which reduced the contingent principal amount. On November 26, 2017, Meredith announced that it had entered into a definitive merger agreement with Time. Pursuant to the merger agreement, upon closing of the merger, a subsidiary of Meredith would purchase for cash all outstanding Time Common shares for $18.50 per share. The transaction was consummated on January 31, 2018. CenterPoint Energy elected to make a reference share offer adjustment and distribute additional interest, if any, in accordance with the terms of its ZENS rather than electing to increase the early exchange ratio to 100%. CenterPoint Energy’s distribution of additional interest in connection with the reference share offer was proportionate to the percentage of eligible shares that were validly tendered by Time stockholders in Meredith’s tender offer. CenterPoint Energy received $18.50 for each share of Time Common held, resulting in cash proceeds of approximately $16 million. In accordance with the terms of the ZENS, CenterPoint Energy distributed additional interest of approximately $16 million to ZENS holders on March 6, 2018, which reduced the contingent principal amount. As a result, CenterPoint Energy recorded the following during the nine months ended September 30, 2018:
CenterPoint Energy’s reference shares for each ZENS consisted of the following:
As of September 30, 2018, the contingent principal amount of the ZENS was $98 million. |
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- Definition This item represents the entire disclosure related to Indexed Debt Securities (ZENS) and Time Warner Securities. No definition available.
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- References No definition available.
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Short-Term Borrowings and Long-term Debt |
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Sep. 30, 2018 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Debt Disclosure [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Short-term Borrowings and Long-term Debt [Text Block] | Short-term Borrowings and Long-term Debt
Inventory Financing. NGD has AMAs associated with its utility distribution service in Arkansas, Louisiana, Mississippi, Oklahoma and Texas. In March 2018, NGD’s third party AMAs in Arkansas, Louisiana and Oklahoma expired, and NGD entered into new AMAs with CES effective April 1, 2018 in these states. The AMAs have varying terms, the longest of which expires in 2021. Pursuant to the provisions of the agreements, NGD sells natural gas and agrees to repurchase an equivalent amount of natural gas during the winter heating seasons at the same cost. These transactions are accounted for as an inventory financing and had an associated principal obligation of $ -0- and $39 million as of September 30, 2018 and December 31, 2017, respectively.
Debt Issuances. During the nine months ended September 30, 2018, the following debt instruments were issued:
The proceeds from these issuances were used for general limited liability company and corporate purposes, as applicable, including to repay portions of outstanding commercial paper and borrowings under CenterPoint Energy’s money pool. Merger Financings. On October 5, 2018, the following debt instruments were issued:
CenterPoint Energy intends to use the net proceeds from these debt issuances to fund a portion of the pending Merger and to pay related fees and expenses. If CenterPoint Energy does not consummate the Merger on or prior to October 31, 2019, or if, on or prior to such date, the Merger Agreement is terminated, CenterPoint Energy will be required to redeem all of the outstanding notes at a redemption price equal to 101% of the principal amount of the notes plus accrued and unpaid interest, if any, to, but excluding, the date of such special mandatory redemption. The notes may also be redeemed at CenterPoint Energy’s option, in whole but not in part, at any time before October 31, 2019, at a redemption price equal to 101% of the aggregate principal amount thereof plus accrued and unpaid interest thereon to, but excluding, the date of such redemption, if CenterPoint Energy determines, in its reasonable judgment, that the Merger will not be consummated on or before close of business on October 31, 2019. Credit Facility. In May 2018, CenterPoint Energy entered into an amendment to its revolving credit facility to increase the aggregate commitments from $1.7 billion to $3.3 billion effective the earlier of (i) the termination of all commitments by certain lenders to provide the Bridge Facility and (ii) the payment in full of all obligations (other than contingent obligations) under the Bridge Facility and termination of all commitments to advance additional credit thereunder, and in each case, so long as the Merger Agreement has not been terminated pursuant to the terms thereof without consummation of the Merger. This increase to CenterPoint Energy’s revolving credit facility will automatically expire on the earlier of the (a) termination date of the revolving credit facility and (b) if the Merger Agreement is terminated without consummation of the Merger, the date that is 90 days after such termination. In addition, the amendment provides for a temporary increase on the maximum ratio of debt for borrowed money to capital from 65% to 75% until the earlier of (i) June 30, 2019 and (ii) the termination of all commitments in respect of the Bridge Facility without any borrowing thereunder. On October 5, 2018, CenterPoint Energy terminated all remaining commitments by lenders to provide the Bridge Facility. As a result, the aggregate commitments under the revolving credit facility automatically increased from $1.7 billion to $3.3 billion and the maximum ratio of debt for borrowed money to capital reverted to 65%. The Registrants had the following revolving credit facilities and utilization of such facilities:
The Registrants were in compliance with all financial debt covenants as of September 30, 2018. Other. As of both September 30, 2018 and December 31, 2017, Houston Electric had issued $118 million of general mortgage bonds as collateral for long-term debt of CenterPoint Energy. These bonds are not reflected in Houston Electric’s consolidated financial statements because of the contingent nature of the obligations. |
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- References No definition available.
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- Definition The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Income Taxes |
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| Income Tax Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Income Taxes [Text Block] | Income Taxes The Registrants reported the following effective tax rates:
The Registrants reported no uncertain tax liability as of September 30, 2018 and expect no significant changes to the uncertain tax liability over the next twelve months. Tax years through 2016 have been audited and settled with the IRS, however, during the three months ended September 30, 2018, CenterPoint Energy filed an amended 2014 tax return to claim additional tax credits that is currently under review by the IRS. For the 2017 and 2018 tax years, CenterPoint Energy is a participant in the IRS’s Compliance Assurance Process. |
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- References No definition available.
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- Definition The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Commitments and Contingencies |
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Sep. 30, 2018 | |||||||||||||||||||||||||||||||||||||||||||||
| Commitments and Contingencies Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||
| Commitments and Contingencies [Text Block] | Commitments and Contingencies
Natural gas supply commitments include natural gas contracts related to CenterPoint Energy’s and CERC’s Natural Gas Distribution and Energy Services business segments, which have various quantity requirements and durations, that are not classified as non-trading derivative assets and liabilities in CenterPoint Energy’s and CERC’s Condensed Consolidated Balance Sheets as of September 30, 2018 and December 31, 2017 as these contracts meet an exception as “normal purchases contracts” or do not meet the definition of a derivative. Natural gas supply commitments also include natural gas transportation contracts that do not meet the definition of a derivative. As of September 30, 2018, minimum payment obligations for natural gas supply commitments are approximately:
Legal Matters Gas Market Manipulation Cases (CenterPoint Energy and CERC). CenterPoint Energy, its predecessor, Reliant Energy, and certain of their former subsidiaries were named as defendants in a large number of lawsuits filed against numerous gas market participants in a number of federal and western state courts in connection with the operation of the natural gas markets in 2000-2002. CenterPoint Energy and its affiliates were released or dismissed from all such cases, except for one case pending in federal court in Nevada in which CES, a subsidiary of CERC Corp., is a defendant. Plaintiffs in that case allege a conspiracy to inflate Wisconsin natural gas prices in 2000-2002. In May 2016, the district court granted CES’s motion for summary judgment, dismissing CES from the case. In August 2018, the Ninth Circuit Court of Appeals reversed that ruling, and CES requested further appellate review of that decision. Under a master separation agreement between CenterPoint Energy and a former subsidiary, RRI, CenterPoint Energy and its subsidiaries are entitled to be indemnified by RRI and its successors for any losses, including certain attorneys’ fees and other costs, arising out of these lawsuits. Through a series of transactions, RRI became known as GenOn and a wholly-owned subsidiary of NRG. None of those transactions alters GenOn’s contractual obligations to indemnify CenterPoint Energy and its subsidiaries for certain liabilities, including their indemnification obligations regarding the gas market manipulation litigation. In June 2017, however, GenOn and various affiliates filed for protection under Chapter 11 of the U.S. Bankruptcy Code and are expected to emerge from Chapter 11 in 2018. CenterPoint Energy, CERC, and CES submitted proofs of claim in the bankruptcy proceedings to protect their indemnity rights. In October 2018, CES, GenOn, and the plaintiffs reached an agreement to settle all claims against CES and CES’s indemnity claims against GenOn, subject to approvals by the bankruptcy court and the federal district court. If the settlement agreement is not approved and if GenOn’s bankruptcy proceedings result in it not being required to fulfill its indemnity obligations, CES could incur liability and be responsible for satisfying it. CenterPoint Energy does not expect the ultimate outcome of this matter to have a material adverse effect on its financial condition, results of operations or cash flows. Minnehaha Academy (CenterPoint Energy and CERC). On August 2, 2017, a natural gas explosion occurred at the Minnehaha Academy in Minneapolis, Minnesota, resulting in the deaths of two school employees, serious injuries to others and significant property damage to the school. CenterPoint Energy, certain of its subsidiaries, including CERC, and the contractor company working in the school have been named in litigation arising out of this incident. CenterPoint Energy has reached confidential settlement agreements with some claimants. Additionally, CenterPoint Energy is cooperating with the ongoing investigation conducted by the National Transportation Safety Board. Further, CenterPoint Energy is contesting approximately $200,000 in fines imposed by the Minnesota Office of Pipeline Safety. In early 2018, the Minnesota Occupational Safety and Health Administration concluded its investigation without any adverse findings against CenterPoint Energy. CenterPoint Energy’s general and excess liability insurance policies provide coverage for third party bodily injury and property damage claims. Environmental Matters MGP Sites (CenterPoint Energy and CERC). CERC and its predecessors operated MGPs in the past. With respect to certain Minnesota MGP sites, CERC has completed state-ordered remediation and continues state-ordered monitoring and water treatment. As of September 30, 2018, CERC had a recorded liability of $7 million for continued monitoring and any future remediation required by regulators in Minnesota. The estimated range of possible remediation costs for the sites for which CERC believes it may have responsibility was $4 million to $30 million based on remediation continuing for 30 to 50 years. The cost estimates are based on studies of a site or industry average costs for remediation of sites of similar size. The actual remediation costs will depend on the number of sites to be remediated, the participation of other PRPs, if any, and the remediation methods used. In addition to the Minnesota sites, the EPA and other regulators have investigated MGP sites that were owned or operated by CERC or may have been owned by one of its former affiliates. CenterPoint Energy and CERC do not expect the ultimate outcome of these matters to have a material adverse effect on the financial condition, results of operations or cash flows of either CenterPoint Energy or CERC. Asbestos. Some facilities owned by the Registrants or their predecessors in interest contain or have contained asbestos insulation and other asbestos-containing materials. The Registrants are from time to time named, along with numerous others, as defendants in lawsuits filed by a number of individuals who claim injury due to exposure to asbestos, and the Registrants anticipate that additional claims may be asserted in the future. Although their ultimate outcome cannot be predicted at this time, the Registrants do not expect these matters, either individually or in the aggregate, to have a material adverse effect on their financial condition, results of operations or cash flows. Other Environmental. From time to time, the Registrants identify the presence of environmental contaminants during operations or on property where predecessor companies have conducted operations. Other such sites involving contaminants may be identified in the future. The Registrants have and expect to continue to remediate any identified sites consistent with state and federal legal obligations. From time to time, the Registrants have received notices, and may receive notices in the future, from regulatory authorities or others regarding status as a PRP in connection with sites found to require remediation due to the presence of environmental contaminants. In addition, the Registrants have been, or may be, named from time to time as defendants in litigation related to such sites. Although the ultimate outcome of such matters cannot be predicted at this time, the Registrants do not expect these matters, either individually or in the aggregate, to have a material adverse effect on their financial condition, results of operations or cash flows. Other Proceedings The Registrants are involved in other legal, environmental, tax and regulatory proceedings before various courts, regulatory commissions and governmental agencies regarding matters arising in the ordinary course of business. From time to time, the Registrants are also defendants in legal proceedings with respect to claims brought by various plaintiffs against broad groups of participants in the energy industry. Some of these proceedings involve substantial amounts. The Registrants regularly analyze current information and, as necessary, provide accruals for probable and reasonably estimable liabilities on the eventual disposition of these matters. The Registrants do not expect the disposition of these matters to have a material adverse effect on the Registrants’ financial condition, results of operations or cash flows. |
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- Definition The entire disclosure for commitments and contingencies. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Earnings Per Share (CenterPoint Energy) |
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| Earnings Per Share [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Earnings Per Share (CenterPoint Energy) [Text Block] | Earnings Per Share (CenterPoint Energy) The following table reconciles numerators and denominators of CenterPoint Energy’s basic and diluted earnings per share calculations:
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- Definition The entire disclosure for earnings per share. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reportable Business Segments |
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Sep. 30, 2018 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Segment Reporting [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Reportable Business Segments [Text Block] | Reportable Business Segments The Registrants’ determination of reportable business segments considers the strategic operating units under which the Registrants manage sales, allocate resources and assess performance of various products and services to wholesale or retail customers in differing regulatory environments. The Registrants use operating income as the measure of profit or loss for the business segments other than Midstream Investments, where equity in earnings is used. As of September 30, 2018, reportable business segments by Registrant are as follows:
Electric Transmission & Distribution consists of the electric transmission and distribution function. Natural Gas Distribution consists of intrastate natural gas sales to, and natural gas transportation and distribution for, residential, commercial, industrial and institutional customers. Energy Services consists of non-rate regulated natural gas sales and services operations. Midstream Investments consists of the equity investment in Enable (excluding the Enable Series A Preferred Units). Other Operations consists primarily of other corporate operations which support all of the business operations. Houston Electric consists of a single reportable business segment and therefore is not included in the tabular business segment presentation below. Operating income (loss) amounts for 2017 have been recast to reflect the adoption of ASU 2017-07 (see Note 2 for further information). Financial data for business segments is as follows: CenterPoint Energy
CERC
CenterPoint Energy and CERC
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- References No definition available.
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| X | ||||||||||
- Definition The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Supplemental Disclosure of Cash Flow Information |
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| Supplemental Cash Flow Elements [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Supplemental Disclosure of Cash Flow Information [Text Block] | Supplemental Disclosure of Cash Flow Information The table below provides supplemental disclosure of cash flow information:
The table below provides a reconciliation of cash, cash equivalents and restricted cash reported in the Condensed Consolidated Balance Sheets to the amount reported in the Condensed Statements of Consolidated Cash Flows:
CERC does not have restricted cash and therefore was not included in the table above. |
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| X | ||||||||||
- Definition The entire disclosure for supplemental cash flow activities, including cash, noncash, and part noncash transactions, for the period. Noncash is defined as information about all investing and financing activities of an enterprise during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- References No definition available.
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Related Party Transactions (Houston Electric and CERC) |
9 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Related Party Transactions [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Related Party Transactions (Houston Electric and CERC) [Text Block] | Related Party Transactions (Houston Electric and CERC) Houston Electric and CERC participate in a money pool through which they can borrow or invest on a short-term basis. Funding needs are aggregated and external borrowing or investing is based on the net cash position. The net funding requirements of the money pool are expected to be met with borrowings under CenterPoint Energy’s revolving credit facility or the sale of CenterPoint Energy’s commercial paper. The table below summarizes money pool activity:
Houston Electric and CERC affiliate related net interest income (expense) were as follows:
CenterPoint Energy provides some corporate services to Houston Electric and CERC. The costs of services have been charged directly to Houston Electric and CERC using methods that management believes are reasonable. These methods include negotiated usage rates, dedicated asset assignment and proportionate corporate formulas based on operating expenses, assets, gross margin, employees and a composite of assets, gross margin and employees. Houston Electric provides certain services to CERC. These services are billed at actual cost, either directly or as an allocation and include fleet services, shop services, geographic services, surveying and right-of-way services, radio communications, data circuit management and field operations. Additionally, CERC provides certain services to Houston Electric. These services are billed at actual cost, either directly or as an allocation and include line locating and other miscellaneous services. These charges are not necessarily indicative of what would have been incurred had Houston Electric and CERC not been affiliates. Amounts charged for these services were as follows and are included primarily in operation and maintenance expenses:
The table below presents transactions among Houston Electric, CERC and their parent, Utility Holding.
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- References No definition available.
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- Definition The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Equity (CenterPoint Energy) |
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| Equity (CenterPoint Energy) [Text Block] | Equity (CenterPoint Energy) Dividends Declared CenterPoint Energy declared dividends for the periods presented in the table below:
Series A Preferred Stock On August 22, 2018, CenterPoint Energy completed the issuance of 800,000 shares of its Series A Preferred Stock, at a price of $1,000 per share, resulting in net proceeds of $790 million after issuance costs. The aggregate liquidation value of the Series A Preferred Stock is $800 million with a per share liquidation value of $1,000. CenterPoint Energy intends to use the net proceeds from the Series A Preferred Stock offering to fund a portion of the pending Merger and to pay related fees and expenses. Dividends. The Series A Preferred Stock accrue cumulative dividends, calculated as a percentage of the stated amount per share, at a fixed annual rate of 6.125% per annum to, but excluding, September 1, 2023, and at an annual rate of three-month LIBOR plus a spread of 3.270% thereafter to be paid in cash if, when and as declared. If declared, prior to September 1, 2023, dividends are payable semi-annually in arrears on each March 1 and September 1, beginning on March 1, 2019, and, for the period commencing on September 1, 2023, dividends are payable quarterly in arrears each March 1, June 1, September 1 and December 1, beginning on December 1, 2023. Cumulative dividends accrued during the applicable periods are presented on CenterPoint Energy’s Condensed Statements of Consolidated Income as Series A Preferred Stock dividend requirement. Optional Redemption. On or after September 1, 2023, CenterPoint Energy may, at its option, redeem the Series A Preferred Stock, in whole or in part, at any time or from time to time, for cash at a redemption price of $1,000 per share, plus any accumulated and unpaid dividends thereon to, but excluding, the redemption date. At any time within 120 days after the conclusion of any review or appeal process instituted by CenterPoint Energy, if any, following the occurrence of a ratings event, CenterPoint Energy may, at its option, redeem the Series A Preferred Stock in whole, but not in part, at a redemption price in cash per share equal to $1,020 (102% of the liquidation value of $1,000) plus an amount equal to all accumulated and unpaid dividends thereon to, but excluding, the redemption date, whether or not declared. Ranking. The Series A Preferred Stock, with respect to anticipated dividends and distributions upon CenterPoint Energy’s liquidation or dissolution, or winding-up of CenterPoint Energy’s affairs, ranks or will rank:
Voting Rights. Holders of the Series A Preferred Stock generally will not have voting rights. Whenever dividends on shares of Series A Preferred Stock have not been declared and paid for the equivalent of three or more semi-annual or six or more quarterly dividend periods (including, for the avoidance of doubt, the dividend period beginning on, and including, the original issue date and ending on, but excluding, March 1, 2019), whether or not consecutive, the holders of such shares of Series A Preferred Stock, voting together as a single class with holders of any and all other series of voting preferred stock (as defined in the Statement of Resolution for the Series A Preferred Stock) then outstanding, will be entitled at CenterPoint Energy’s next annual or special meeting of shareholders to vote for the election of a total of two additional members of CenterPoint Energy’s Board of Directors, subject to certain limitations. This right will terminate if and when all accumulated dividends have been paid in full and, upon such termination, the term of office of each director so elected will terminate at such time and the number of directors on CenterPoint Energy’s Board of Directors will automatically decrease by two, subject to the revesting of such rights in the event of each subsequent nonpayment. Series B Preferred Stock On October 1, 2018, CenterPoint Energy completed the issuance of 19,550,000 depositary shares, each representing a 1/20th interest in a share of its Series B Preferred Stock, at a price of $50 per depositary share, resulting in net proceeds of $950 million after issuance costs. The aggregate liquidation value of Series B Preferred Stock is $978 million with a per share liquidation value of $1,000. The amount issued included 2,550,000 depositary shares issued pursuant to the exercise in full of the option granted to the underwriters to purchase additional depositary shares. CenterPoint Energy intends to use the net proceeds from the offering of depositary shares, each representing a 1/20th interest in a share of Series B Preferred Stock, to fund a portion of the pending Merger and to pay related fees and expenses. Dividends. Dividends on the Series B Preferred Stock will be payable on a cumulative basis when, as and if declared at an annual rate of 7.00% on the liquidation value of $1,000 per share. CenterPoint Energy may pay declared dividends in cash or, subject to certain limitations, in shares of Common Stock, or in any combination of cash and shares of Common Stock on March 1, June 1, September 1 and December 1 of each year, commencing on December 1, 2018 and ending on, and including, September 1, 2021. Acquisition Termination Redemption. If the pending Merger has not closed at or prior to close of business on April 21, 2019 or if an acquisition termination event occurs, CenterPoint Energy may, at its option, give notice of an acquisition termination redemption to the holders of the Series B Preferred Stock. If CenterPoint Energy provides such notice, then, on the acquisition termination redemption date, CenterPoint Energy will be required to redeem the Series B Preferred Stock, in whole but not in part, at a redemption amount per share of the Series B Preferred Stock equal to the acquisition termination redemption amount. CenterPoint Energy will pay the acquisition termination redemption amount in cash unless the acquisition termination share price is greater than the initial price, in which case CenterPoint Energy will instead pay the acquisition termination redemption amount by delivering shares of Common Stock and cash; provided, that CenterPoint Energy may elect, subject to certain limitations, to pay cash or deliver shares of Common Stock in lieu of these amounts. If CenterPoint Energy redeems shares of the Series B Preferred Stock held by the depositary, the depositary will redeem, on the same acquisition termination redemption date, the number of the depositary shares representing the shares of the Series B Preferred Stock so redeemed. Mandatory Conversion. Unless earlier converted or redeemed, each share of the Series B Preferred Stock will automatically convert on the mandatory conversion date, which is expected to be September 1, 2021, into not less than 30.5820 and not more than 36.6980 shares of Common Stock, subject to certain anti-dilution adjustments. Correspondingly, the conversion rate per depositary share will be not less than 1.5291 and not more than 1.8349 shares of Common Stock, subject to certain anti-dilution adjustments. The conversion rate will be determined based on a preceding 20-day volume-weighted-average-price of Common Stock. The following table illustrates the conversion rate per share of the Series B Preferred Stock, subject to certain anti-dilution adjustments:
The following table illustrates the conversion rate per depositary share, subject to certain anti-dilution adjustments:
Optional Conversion of the Holder. Other than during a fundamental change conversion period, and unless CenterPoint Energy has redeemed the Series B Preferred Stock, a holder of the Series B Preferred Stock may, at any time prior to September 1, 2021, elect to convert such holder’s shares of the Series B Preferred Stock, in whole or in part, at the minimum conversion rate of 30.5820 shares of Common Stock per share of the Series B Preferred Stock (equivalent to 1.5291 shares of Common Stock per depositary share), subject to certain anti-dilution and other adjustments. Because each depositary share represents a 1/20th fractional interest in a share of the Series B Preferred Stock, a holder of depositary shares may convert its depositary shares only in lots of 20 depositary shares. Fundamental Change Conversion. If a fundamental change occurs on or prior to September 1, 2021, holders of the Series B Preferred Stock will have the right to convert their shares of the Series B Preferred Stock, in whole or in part, into shares of Common Stock at the fundamental change conversion rate during the period beginning on, and including, the effective date of such fundamental change and ending on, and including, the date that is 20 calendar days after such effective date (or, if later, the date that is 20 calendar days after holders receive notice of such fundamental change, but in no event later than September 1, 2021). Holders who convert shares of the Series B Preferred Stock during that period will also receive a make-whole dividend amount comprised of a fundamental change dividend make-whole amount, and to the extent there is any, the accumulated dividend amount. Because each depositary share represents a 1/20th fractional interest in a share of the Series B Preferred Stock, a holder of depositary shares may convert its depositary shares upon a fundamental change only in lots of 20 depositary shares. Ranking. The Series B Preferred Stock, with respect to anticipated dividends and distributions upon CenterPoint Energy’s liquidation or dissolution, or winding-up of CenterPoint Energy’s affairs, ranks or will rank:
Voting Rights. Holders of the Series B Preferred Stock generally will not have voting rights. Whenever dividends on shares of the Series B Preferred Stock have not been declared and paid for six or more dividend periods (including, for the avoidance of doubt, the dividend period beginning on, and including, the initial issue date and ending on, but excluding, December 1, 2018), whether or not consecutive, the holders of such shares of Series B Preferred Stock, voting together as a single class with holders of any and all other series of voting preferred stock then outstanding (as defined in the Statement of Resolution for the Series B Preferred Stock), will be entitled at CenterPoint Energy’s next annual or special meeting of shareholders to vote for the election of a total of two additional members of CenterPoint Energy’s Board of Directors, subject to certain limitations. This right will terminate if and when all accumulated and unpaid dividends have been paid in full and, upon such termination, the term of office of each director so elected will terminate at such time and the number of directors on CenterPoint Energy’s Board of Directors will automatically decrease by two, subject to the revesting of such rights in the event of each subsequent nonpayment. Common Stock On October 1, 2018, CenterPoint Energy completed the issuance of approximately 69,633,027 shares of Common Stock at a price of $27.25 per share, for net proceeds of $1,844 million after issuance costs. The amount issued included 9,082,568 shares of Common Stock issued pursuant to the exercise in full of the option granted to the underwriters to purchase additional shares of Common Stock. CenterPoint Energy intends to use the net proceeds from the Common Stock offering to fund a portion of the pending Merger and to pay related fees and expenses. |
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- References No definition available.
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- Definition The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Subsequent Events (CenterPoint Energy and CERC) |
9 Months Ended |
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Sep. 30, 2018 | |
| Subsequent Events [Abstract] | |
| Subsequent Events (CenterPoint Energy and CERC) [Text Block] | Subsequent Events (CenterPoint Energy) CenterPoint Energy Dividend Declarations On October 23, 2018, CenterPoint Energy’s Board of Directors declared a regular quarterly cash dividend of $0.2775 per share of Common Stock payable on December 13, 2018 to shareholders of record as of the close of business on November 15, 2018. On October 23, 2018, CenterPoint Energy’s Board of Directors declared a regular quarterly cash dividend of $11.6667 per share of the newly issued Series B Preferred Stock ($0.5833 per depository share) payable on December 1, 2018 to shareholders of record as of the close of business on November 15, 2018. For more information about the Series B Preferred Stock, see Note 19. Enable Distributions Declarations On November 6, 2018, Enable declared a quarterly cash distribution of $0.318 per unit on all of its outstanding common units for the quarter ended September 30, 2018. Accordingly, CNP Midstream expects to receive a cash distribution of approximately $74 million from Enable in the fourth quarter of 2018 to be made with respect to CNP Midstream’s investment in common units of Enable. On November 6, 2018, Enable declared a quarterly cash distribution of $0.625 per Series A Preferred Unit for the quarter ended September 30, 2018. Accordingly, CenterPoint Energy expects to receive a cash distribution of approximately $9 million from Enable in the fourth quarter of 2018 to be made with respect to CenterPoint Energy’s investment in Enable Series A Preferred Units. Merger Financing Transactions On October 1, 2018, CenterPoint Energy completed concurrent equity offerings of depositary shares, each representing a 1/20th interest in a share of Series B Preferred Stock, and Common Stock. For more information about the concurrent equity offerings, see Note 19. On October 5, 2018, CenterPoint Energy issued $1.5 billion aggregate principal amount of senior notes. For more information about the senior notes offering, see Note 12. |
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- References No definition available.
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- Definition The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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New Accounting Pronouncements (Tables) |
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| New Accounting Pronouncements and Changes in Accounting Principles [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] | The following table provides an overview of recently adopted or issued accounting pronouncements applicable to all the Registrants, unless otherwise noted.
The table below reflects the impact of adoption of ASU 2017-07:
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- References No definition available.
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- Definition Tabular disclosure of changes in accounting principles, including adoption of new accounting pronouncements, that describes the new methods, amount and effects on financial statement line items. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Revenue Recognition (Tables) |
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Sep. 30, 2018 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Revenue from Contract with Customer [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Disaggregation of Revenue [Table Text Block] | The following tables disaggregate revenues by reportable business segment and major source: CenterPoint Energy
Houston Electric
CERC
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| X | ||||||||||
- Definition Tabular disclosure of disaggregation of revenue into categories depicting how nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factor. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- References No definition available.
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Employee Benefit Plans (Tables) |
9 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Sep. 30, 2018 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Retirement Benefits [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Defined Benefit Plans Disclosures [Table Text Block] | The table below reflects the expected contributions to be made to the pension plans and postretirement benefit plan during 2018:
The table below reflects the contributions made to the pension plans and postretirement benefit plan during 2018:
The Registrants’ net periodic cost, before considering amounts subject to overhead allocations for capital expenditure projects or for amounts subject to deferral for regulatory purposes, includes the following components relating to pension and postretirement benefits: Pension Benefits (CenterPoint Energy)
Postretirement Benefits
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| Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] | Changes in accumulated other comprehensive loss related to defined benefit and postretirement plans are as follows: CenterPoint Energy
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Tabular disclosure of the net gain (loss) and net prior service cost or credit recognized in other comprehensive income (loss) for the period for pension plans and/or other employee benefit plans, and reclassification adjustments of other comprehensive income (loss) for the period, as those amounts, including amortization of the net transition asset or obligation, are recognized as components of net periodic benefit cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Tabular disclosure of one or more of the entity's defined benefit pension plans or one or more other defined benefit postretirement plans, separately for pension plans and other postretirement benefit plans including the entity's schedule of fair value of plan assets for defined benefit or other postretirement plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Regulatory Accounting (Tables) |
9 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Regulatory Assets and Liabilities, Other Disclosures [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Regulatory Assets and Liabilities [Table Text Block] | The following is a list of regulatory assets and liabilities reflected on the Registrants’ Condensed Consolidated Balance Sheets:
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| X | ||||||||||
- Definition Schedule of Regulatory Assets and Liabilities [Table Text Block] No definition available.
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- References No definition available.
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Derivative Instruments (Tables) |
9 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Derivative Instruments and Hedging Activities Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] | The table below summarizes CenterPoint Energy’s and CERC’s current weather hedge gain (loss) activity:
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| Fair Value of Derivative Instruments [Table Text Block] | The following tables present information about derivative instruments and hedging activities. The first two tables provide a balance sheet overview of Derivative Assets and Liabilities, while the last table provides a breakdown of the related income statement impacts. Fair Value of Derivative Instruments and Hedged Items
Cumulative Basis Adjustment for Fair Value Hedges (CenterPoint Energy and CERC)
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| Offsetting of Natural Gas Derivative Assets and Liabilities [Table Text Block] | Offsetting of Natural Gas Derivative Assets and Liabilities (CenterPoint Energy and CERC)
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| Income Statement Impact of Derivative Activity [Table Text Block] | Income Statement Impact of Hedge Accounting Activity (CenterPoint Energy and CERC)
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| Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block] | Effect of Cash Flow Hedge Accounting on Accumulated Other Comprehensive Income
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| Disclosure of Credit Derivatives [Table Text Block] | CenterPoint Energy and CERC enter into financial derivative contracts containing material adverse change provisions. These provisions could require CenterPoint Energy or CERC to post additional collateral if the S&P or Moody’s credit ratings of CenterPoint Energy, Inc. or its subsidiaries, including CERC Corp., are downgraded. CenterPoint Energy and CERC
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- Definition Tabular disclosure of derivative assets and liabilities that are subject to offsetting, including master netting arrangements. No definition available.
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- References No definition available.
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- Definition Tabular disclosure of credit derivatives which includes information by sellers of credit derivatives, about each credit derivative, or each group of similar credit derivatives, including (a) the nature of the credit derivative - its term, how it arose, the events or circumstances that would require the seller to perform under the credit derivative, and the current status of the payment/performance risk of the credit derivative; (b) the maximum potential amount of future payments (undiscounted) the seller could be required to make under the credit derivative; (c) the current fair value of the credit derivative; and (d) the nature of any recourse provisions under the credit derivative, and any assets held either as collateral or by third parties. A credit derivative is a derivative instrument (1) in which one or more of its underlyings are related to the credit risk of a specified entity (or a group of entities) or an index based on the credit risk of a group of entities and (2) that exposes the seller to potential loss from credit-risk-related events specified in the contract. Examples of credit derivatives within the scope of this paragraph include, but are not limited to, credit default swaps, credit spread options, and credit index products; also includes a hybrid instrument that has an embedded credit derivative (for example, but not limited to, a credit-linked note). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Tabular disclosure of the effective portion of the gains and losses on derivative instruments designated (and non-derivative instruments) designated and qualifying in cash flow hedges and net investment hedges that was recognized in other comprehensive income (loss) during the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Tabular disclosure of the location and amount of derivative instruments and nonderivative instruments designated as hedging instruments reported before netting adjustments, and the amount of gain (loss) on derivative instruments and nonderivative instruments designated and qualified as hedging instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Tabular disclosure for fair value hedging instruments of (a) the location and amount of gains and losses reported in the statement of financial performance and (b) the location and fair value amounts of the instruments reported in the statement of financial position. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair Value Measurements (Tables) |
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| Fair Value Disclosures [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Fair value, assets and liabilities measured on a recurring basis [Table Text Block] | The following tables present information about the Registrants’ assets and liabilities (including derivatives that are presented net) measured at fair value on a recurring basis and indicate the fair value hierarchy of the valuation techniques utilized by the Registrants to determine such fair value. CenterPoint Energy
Houston Electric
CERC
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| Assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs [Table Text Block] | The following table presents additional information about assets or liabilities, including derivatives that are measured at fair value on a recurring basis for which CenterPoint Energy and CERC have utilized Level 3 inputs to determine fair value:
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| Estimated fair value of financial instruments, debt instruments [Table Text Block] | The fair values of cash and cash equivalents, investments in debt and equity securities classified as “trading” and short-term borrowings are estimated to be approximately equivalent to carrying amounts and have been excluded from the table below. The carrying amounts of non-trading derivative assets and liabilities and CenterPoint Energy’s ZENS indexed debt securities derivative are stated at fair value and are excluded from the table below. The fair value of each debt instrument is determined by multiplying the principal amount of each debt instrument by a combination of historical trading prices and comparable issue data. These liabilities, which are not measured at fair value in the Registrants’ Condensed Consolidated Balance Sheets, but for which the fair value is disclosed, would be classified as Level 2 in the fair value hierarchy.
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- Definition Tabular disclosure of the fair value measurement of assets using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income (loss), and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Tabular disclosure of the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Unconsolidated Affiliate (CenterPoint Energy and CERC) (Tables) |
9 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Equity Method Investments and Joint Ventures [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Equity Method Investments [Table Text Block] | Interests Held in Enable GP (CenterPoint Energy):
Distributions Received from Enable (CenterPoint Energy and CERC):
Transactions with Enable (CenterPoint Energy and CERC):
Summarized unaudited consolidated income information for Enable is as follows:
Summarized unaudited consolidated balance sheet information for Enable is as follows:
Limited Partner Interest and Units Held in Enable (CenterPoint Energy):
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| Discontinued Operations (CERC) [Table Text Block] | The Internal Spin represents a significant strategic shift that has a material effect on CERC’s operations and financial results and, as a result, CERC’s distribution of its equity investment in Enable met the criteria for discontinued operations classification. CERC has no continuing involvement in the equity investment of Enable. Therefore, CERC’s equity in earnings and related income taxes have been classified as Income from discontinued operations, net of tax, in CERC’s Condensed Statements of Consolidated Income for the periods presented. CERC’s equity method investment and related deferred income tax liabilities have been classified as Investment in unconsolidated affiliate - discontinued operations and Deferred income taxes, net - discontinued operations, respectively, in CERC’s Condensed Consolidated Balance Sheets for the periods presented. The following table presents amounts included in Income from discontinued operations, net of tax in CERC’s Condensed Statements of Consolidated Income.
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- References No definition available.
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- Definition Tabular disclosure of equity method investments including, but not limited to, name of each investee or group of investments, percentage ownership, difference between recorded amount of an investment and the value of the underlying equity in the net assets, and summarized financial information. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Goodwill and Other Intangibles (CenterPoint Energy and CERC) (Tables) |
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Sep. 30, 2018 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Goodwill and Intangible Assets Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Goodwill [Table Text Block] | CenterPoint Energy’s and CERC’s goodwill by reportable business segment as of both September 30, 2018 and December 31, 2017 is as follows:
(1) Amount presented is net of the accumulated goodwill impairment charge of $252 million recorded in 2012. |
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| Schedule of Finite-Lived Intangible Assets [Table Text Block] | The tables below present information on CenterPoint Energy’s and CERC’s other intangible assets recorded in Other non-current assets on the Condensed Consolidated Balance Sheets.
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| Finite-lived Intangible Assets Amortization Expense [Table Text Block] |
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- Definition Tabular disclosure of amortization expense of assets, excluding financial assets, that lack physical substance, having a limited useful life. No definition available.
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- References No definition available.
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- Definition Tabular disclosure of assets, excluding financial assets and goodwill, lacking physical substance with a finite life, by either major class or business segment. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) (Tables) |
9 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Sep. 30, 2018 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Investments, Debt and Equity Securities [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Indexed Debt Securities and Marketable Securities [Table Text Block] | As a result, CenterPoint Energy recorded the following during the nine months ended September 30, 2018:
CenterPoint Energy’s reference shares for each ZENS consisted of the following:
In 1995, CenterPoint Energy sold a cable television subsidiary to TW and received certain TW securities as partial consideration. A subsidiary of CenterPoint Energy holds shares of certain securities detailed in the table below, which are classified as trading securities and are expected to be held to facilitate CenterPoint Energy’s ability to meet its obligation under the ZENS. Unrealized gains and losses resulting from changes in the market value of the ZENS-Related Securities are recorded in CenterPoint Energy’s Condensed Statements of Consolidated Income.
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- Definition Schedule of Indexed Debt Securities and Marketable Securities [Table Text Block] No definition available.
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- References No definition available.
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Short-Term Borrowings and Long-term Debt (Tables) |
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| Debt Disclosure [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Debt [Table Text Block] | Debt Issuances. During the nine months ended September 30, 2018, the following debt instruments were issued:
The proceeds from these issuances were used for general limited liability company and corporate purposes, as applicable, including to repay portions of outstanding commercial paper and borrowings under CenterPoint Energy’s money pool. Merger Financings. On October 5, 2018, the following debt instruments were issued:
CenterPoint Energy intends to use the net proceeds from these debt issuances to fund a portion of the pending Merger and to pay related fees and expenses. |
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| Schedule of Line of Credit Facilities [Table Text Block] | The Registrants had the following revolving credit facilities and utilization of such facilities:
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- References No definition available.
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- Definition Tabular disclosure of information pertaining to short-term and long-debt instruments or arrangements, including but not limited to identification of terms, features, collateral requirements and other information necessary to a fair presentation. No definition available.
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- Definition Tabular disclosure of short-term or long-term contractual arrangements with lenders, including letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Income Taxes (Tables) |
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| Income Tax Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] | The Registrants reported the following effective tax rates:
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- Definition Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Commitments and Contingencies (Tables) |
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Sep. 30, 2018 | |||||||||||||||||||||||||||||||||||||
| Commitments and Contingencies Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||
| Long-term Purchase Commitment [Table Text Block] | As of September 30, 2018, minimum payment obligations for natural gas supply commitments are approximately:
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- Definition Tabular disclosure of key provisions of an arrangement under which the entity has agreed to purchase goods or services over a period of time greater than one year or the normal operating cycle, if longer, including the item for which expenditures will be made, minimum quantities, milestones, time period and committed amount. No definition available.
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Earnings Per Share (CenterPoint Energy) (Tables) |
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| Earnings Per Share [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] | The following table reconciles numerators and denominators of CenterPoint Energy’s basic and diluted earnings per share calculations:
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- Definition Tabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reportable Business Segments (Tables) |
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| Segment Reporting [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Segment Reporting Information, by Segment [Table Text Block] | Financial data for business segments is as follows: CenterPoint Energy
CERC
CenterPoint Energy and CERC
As of September 30, 2018, reportable business segments by Registrant are as follows:
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| Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block] | CenterPoint Energy’s and Houston Electric’s Electric Transmission & Distribution revenues from major customers are as follows:
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| Midstream Investments [Table Text Block] | CenterPoint Energy’s Midstream Investments’ equity earnings, net are as follows:
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- Definition Tabular presentation of equity earnings and equity investment related to Midstream Investments for the period [Table Text Block] No definition available.
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| X | ||||||||||
- Definition Tabular disclosure of the extent of the entity's reliance on its major customers, if revenues from transactions with a single external customer amount to 10 percent or more of entity revenues, including the disclosure of that fact, the total amount of revenues from each such customer, and the identity of the reportable segment or segments reporting the revenues. The entity need not disclose the identity of a major customer or the amount of revenues that each segment reports from that customer. For these purposes, a group of companies known to the entity to be under common control is considered a single customer, and the federal government, a state government, a local government such as a county or municipality, or a foreign government is each considered a single customer. No definition available.
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| X | ||||||||||
- Definition Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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Supplemental Disclosure of Cash Flow Information (Tables) |
9 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Supplemental Cash Flow Elements [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] | The table below provides supplemental disclosure of cash flow information:
The table below provides a reconciliation of cash, cash equivalents and restricted cash reported in the Condensed Consolidated Balance Sheets to the amount reported in the Condensed Statements of Consolidated Cash Flows:
CERC does not have restricted cash and therefore was not included in the table above. |
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- Definition Tabular disclosure of supplemental cash flow information for the periods presented. No definition available.
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- References No definition available.
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Related Party Transactions (Houston Electric and CERC) (Tables) |
9 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Related Party Transactions [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Schedule of Money Pool Investment and Borrowing [Table Text Block] | The table below summarizes money pool activity:
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| Schedule of Related Party Transactions [Table Text Block] | Houston Electric and CERC affiliate related net interest income (expense) were as follows:
Amounts charged for these services were as follows and are included primarily in operation and maintenance expenses:
The table below presents transactions among Houston Electric, CERC and their parent, Utility Holding.
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- Definition Tabular disclosure of related party transactions. Examples of related party transactions include, but are not limited to, transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners and (d) affiliates. No definition available.
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Equity (CenterPoint Energy) (Tables) |
9 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2018 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Equity [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dividends Declared [Table Text Block] | CenterPoint Energy declared dividends for the periods presented in the table below:
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| Convertible Debt [Table Text Block] | The following table illustrates the conversion rate per share of the Series B Preferred Stock, subject to certain anti-dilution adjustments:
The following table illustrates the conversion rate per depositary share, subject to certain anti-dilution adjustments:
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Background and Basis of Presentation (Details) |
9 Months Ended | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Sep. 30, 2018
state
shares
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| Enable Midstream Partners [Member] | ||||||||||||||
| Ownership percentage of equity method investment | 54.00% | [1],[2] | ||||||||||||
| Enable Midstream Partners [Member] | Series A Preferred Units [Member] | ||||||||||||||
| Preferred units held | shares | 14,520,000 | [2],[3] | ||||||||||||
| Natural Gas Distribution [Member] | ||||||||||||||
| Number of states in which entity operates | 6 | |||||||||||||
| Energy Services [Member] | ||||||||||||||
| Number of states in which entity operates | 33 | |||||||||||||
| Enable GP, LLC [Member] | CenterPoint Energy [Member] | ||||||||||||||
| Management rights ownership percentage | 50.00% | [4],[5] | ||||||||||||
| Incentive distribution right | 40.00% | [5],[6] | ||||||||||||
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Pending Merger with Vectren (CenterPoint Energy) (Details) $ / shares in Units, $ in Millions |
9 Months Ended | ||
|---|---|---|---|
Oct. 01, 2018 |
Sep. 30, 2018
USD ($)
$ / shares
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Dec. 31, 2017
USD ($)
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|
| Amount of cash to be paid to acquire Vectren | $ 6,000 | ||
| Cash to be paid per share of Vectren common stock prior to closing of the Merger | $ / shares | $ 72.00 | ||
| Short-term debt | $ 0 | $ 39 | |
| Anticipated amount of short and long-term debt at the closing of the Merger | 2,500 | ||
| Vectren [Member] | |||
| Short-term debt | 325 | ||
| Long-term debt, including current maturities | 2,000 | ||
| Termination fee | 150 | ||
| CenterPoint Energy [Member] | |||
| Termination fee | $ 210 | ||
| Series B Preferred Stock [Member] | Subsequent Event [Member] | |||
| Depositary share interest in a share of Series B Preferred Stock | 0.05 |
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- Definition Revenue derived from derivative natural gas sales contracts, asset management agreements and gains (losses) associated with weather hedge derivatives. No definition available.
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- Definition Amount, excluding tax collected from customer, of alternative revenue programs and leases revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. No definition available.
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Employee Benefit Plans (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
||||||||
| Defined Benefit Plan, Change in Accumulated Comprehensive Loss [Roll Forward] | |||||||||||
| Beginning Balance | $ (63) | $ (70) | $ (66) | $ (72) | |||||||
| Amounts reclassified from accumulated other comprehensive loss: | |||||||||||
| Prior service cost (1) | [1] | 0 | 0 | 1 | 1 | ||||||
| Actuarial losses (1) | [1] | 2 | 2 | 5 | 5 | ||||||
| Tax expense | (1) | (2) | (2) | (4) | |||||||
| Net current period other comprehensive income | 1 | 0 | 4 | 2 | |||||||
| Ending Balance | (62) | (70) | (62) | (70) | |||||||
| Pension Benefits [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Net periodic cost (credit) | 16 | 23 | 46 | 71 | |||||||
| Total contributions expected in current year | 67 | 67 | |||||||||
| Total contributions to the plans during the period | 3 | 67 | |||||||||
| Other Postretirement Benefits Plan [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Net periodic cost (credit) | 1 | 2 | 4 | 6 | |||||||
| Total contributions expected in current year | 16 | 16 | |||||||||
| Total contributions to the plans during the period | 4 | 11 | |||||||||
| Operation and maintenance expense [Member] | Pension Benefits [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Service cost (1) | [2] | 10 | 9 | 28 | 27 | ||||||
| Operation and maintenance expense [Member] | Other Postretirement Benefits Plan [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Service cost (1) | [2] | 0 | 0 | 1 | 1 | ||||||
| Other, net [Member] | Pension Benefits [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Interest cost (2) | [3] | 20 | 22 | 59 | 66 | ||||||
| Expected return on plan assets (2) | [3] | (27) | (24) | (80) | (72) | ||||||
| Amortization of prior service cost (credit) (2) | [3] | 3 | 2 | 7 | 7 | ||||||
| Amortization of net loss (2) | [3] | 10 | 14 | 32 | 43 | ||||||
| Other, net [Member] | Other Postretirement Benefits Plan [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Interest cost (2) | [3] | 3 | 4 | 10 | 12 | ||||||
| Expected return on plan assets (2) | [3] | (1) | (1) | (4) | (4) | ||||||
| Amortization of prior service cost (credit) (2) | [3] | (1) | (1) | (3) | (3) | ||||||
| Houston Electric [Member] | Other Postretirement Benefits Plan [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Net periodic cost (credit) | 0 | 0 | (1) | 0 | |||||||
| Total contributions expected in current year | 10 | 10 | |||||||||
| Total contributions to the plans during the period | 3 | 7 | |||||||||
| Houston Electric [Member] | Operation and maintenance expense [Member] | Other Postretirement Benefits Plan [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Service cost (1) | [2] | 0 | 0 | 0 | 0 | ||||||
| Houston Electric [Member] | Other, net [Member] | Other Postretirement Benefits Plan [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Interest cost (2) | [3] | 2 | 3 | 6 | 7 | ||||||
| Expected return on plan assets (2) | [3] | (1) | (1) | (3) | (3) | ||||||
| Amortization of prior service cost (credit) (2) | [3] | (1) | (2) | (4) | (4) | ||||||
| CERC Corp [Member] | Other Postretirement Benefits Plan [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Net periodic cost (credit) | 2 | 1 | 4 | 4 | |||||||
| Total contributions expected in current year | 5 | 5 | |||||||||
| Total contributions to the plans during the period | 1 | 3 | |||||||||
| CERC Corp [Member] | Operation and maintenance expense [Member] | Other Postretirement Benefits Plan [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Service cost (1) | [2] | 1 | 1 | 1 | 1 | ||||||
| CERC Corp [Member] | Other, net [Member] | Other Postretirement Benefits Plan [Member] | |||||||||||
| Defined Benefit Plan Disclosure [Line Items] | |||||||||||
| Interest cost (2) | [3] | 1 | 1 | 3 | 3 | ||||||
| Expected return on plan assets (2) | [3] | 0 | (1) | (1) | (1) | ||||||
| Amortization of prior service cost (credit) (2) | [3] | $ 0 | $ 0 | $ 1 | $ 1 | ||||||
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- Definition Defined Benefit Plan, Change in Accumulated Comprehensive Loss [Roll Forward] No definition available.
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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of contribution received by defined benefit plan from employer which increases plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Amount of contributions received and expected to be received by defined benefit plan from employer in current fiscal year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income for defined benefit plan, attributable to parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount, before tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Regulatory Accounting (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
Dec. 31, 2017 |
||||||||||||||||
| Securitized regulatory assets | $ 1,146 | $ 1,146 | $ 1,590 | |||||||||||||||||
| Unrecognized equity return (2) | [1] | (225) | (225) | (287) | ||||||||||||||||
| Unamortized loss on reacquired debt | 70 | 70 | 75 | |||||||||||||||||
| Regulatory assets | 1,934 | 1,934 | 2,347 | |||||||||||||||||
| Total regulatory assets | 1,994 | 1,994 | 2,477 | |||||||||||||||||
| Regulatory liabilities | 2,506 | 2,506 | 2,464 | |||||||||||||||||
| Total regulatory liabilities | 2,553 | 2,553 | 2,488 | |||||||||||||||||
| Total regulatory assets and liabilities, net | (559) | (559) | (11) | |||||||||||||||||
| Houston Electric [Member] | ||||||||||||||||||||
| Securitized regulatory assets | 1,146 | 1,146 | 1,590 | |||||||||||||||||
| Unrecognized equity return (2) | [1] | (225) | (225) | (287) | ||||||||||||||||
| Unamortized loss on reacquired debt | 70 | 70 | 75 | |||||||||||||||||
| Regulatory assets | 1,202 | 1,202 | 1,570 | |||||||||||||||||
| Total regulatory assets | 1,202 | 1,202 | 1,570 | |||||||||||||||||
| Regulatory liabilities | 1,265 | 1,265 | 1,263 | |||||||||||||||||
| Total regulatory liabilities | 1,287 | 1,287 | 1,285 | |||||||||||||||||
| Total regulatory assets and liabilities, net | (85) | (85) | 285 | |||||||||||||||||
| Amount of allowed equity return on the true-up balance that was recognized in the period | 17 | $ 13 | 62 | $ 30 | ||||||||||||||||
| CERC Corp [Member] | ||||||||||||||||||||
| Securitized regulatory assets | 0 | 0 | 0 | |||||||||||||||||
| Unrecognized equity return (2) | [1] | 0 | 0 | 0 | ||||||||||||||||
| Unamortized loss on reacquired debt | 0 | 0 | 0 | |||||||||||||||||
| Regulatory assets | 170 | 170 | 181 | |||||||||||||||||
| Total regulatory assets | 230 | 230 | 311 | |||||||||||||||||
| Regulatory liabilities | 1,241 | 1,241 | 1,201 | |||||||||||||||||
| Total regulatory liabilities | 1,266 | 1,266 | 1,203 | |||||||||||||||||
| Total regulatory assets and liabilities, net | (1,036) | (1,036) | (892) | |||||||||||||||||
| Hurricane Harvey [Member] | ||||||||||||||||||||
| Regulatory assets | [2] | 67 | 67 | 64 | ||||||||||||||||
| Hurricane Harvey [Member] | Houston Electric [Member] | ||||||||||||||||||||
| Regulatory assets | [2] | 61 | 61 | 58 | ||||||||||||||||
| Hurricane Harvey [Member] | CERC Corp [Member] | ||||||||||||||||||||
| Regulatory assets | [2] | 6 | 6 | 6 | ||||||||||||||||
| Prepaid expenses and other current assets [Member] | ||||||||||||||||||||
| Current regulatory assets (1) | [3] | 60 | 60 | 130 | ||||||||||||||||
| Prepaid expenses and other current assets [Member] | Houston Electric [Member] | ||||||||||||||||||||
| Current regulatory assets (1) | [3] | 0 | 0 | 0 | ||||||||||||||||
| Prepaid expenses and other current assets [Member] | CERC Corp [Member] | ||||||||||||||||||||
| Current regulatory assets (1) | [3] | 60 | 60 | 130 | ||||||||||||||||
| Other current liabilities [Member] | ||||||||||||||||||||
| Current regulatory liabilities (7) | [4] | 47 | 47 | 24 | ||||||||||||||||
| Other current liabilities [Member] | Houston Electric [Member] | ||||||||||||||||||||
| Current regulatory liabilities (7) | [4] | 22 | 22 | 22 | ||||||||||||||||
| Other current liabilities [Member] | CERC Corp [Member] | ||||||||||||||||||||
| Current regulatory liabilities (7) | [4] | 25 | 25 | 2 | ||||||||||||||||
| Pension and Other Postretirement Plans Costs [Member] | ||||||||||||||||||||
| Regulatory assets | [5] | 609 | 609 | 646 | ||||||||||||||||
| Pension and Other Postretirement Plans Costs [Member] | Houston Electric [Member] | ||||||||||||||||||||
| Regulatory assets | [5] | 32 | 32 | 31 | ||||||||||||||||
| Pension and Other Postretirement Plans Costs [Member] | CERC Corp [Member] | ||||||||||||||||||||
| Regulatory assets | [5] | 15 | 15 | 20 | ||||||||||||||||
| Amounts related to TCJA [Member] | ||||||||||||||||||||
| Regulatory assets | [6] | 48 | 48 | 48 | ||||||||||||||||
| Amounts related to TCJA [Member] | Houston Electric [Member] | ||||||||||||||||||||
| Regulatory assets | [6] | 34 | 34 | 33 | ||||||||||||||||
| Amounts related to TCJA [Member] | CERC Corp [Member] | ||||||||||||||||||||
| Regulatory assets | [6] | 14 | 14 | 15 | ||||||||||||||||
| Other Regulatory Assets (Liabilities) [Member] | ||||||||||||||||||||
| Regulatory assets | [7] | 219 | 219 | 211 | ||||||||||||||||
| Other Regulatory Assets (Liabilities) [Member] | Houston Electric [Member] | ||||||||||||||||||||
| Regulatory assets | [7] | 84 | 84 | 70 | ||||||||||||||||
| Other Regulatory Assets (Liabilities) [Member] | CERC Corp [Member] | ||||||||||||||||||||
| Regulatory assets | [7] | 135 | 135 | 140 | ||||||||||||||||
| Amounts related to TCJA [Member] | ||||||||||||||||||||
| Regulatory liabilities | [6] | 1,362 | 1,362 | 1,354 | ||||||||||||||||
| Amounts related to TCJA [Member] | Houston Electric [Member] | ||||||||||||||||||||
| Regulatory liabilities | [6] | 858 | 858 | 862 | ||||||||||||||||
| Amounts related to TCJA [Member] | CERC Corp [Member] | ||||||||||||||||||||
| Regulatory liabilities | [6] | 504 | 504 | 492 | ||||||||||||||||
| Removal Costs [Member] | ||||||||||||||||||||
| Regulatory liabilities | 887 | 887 | 878 | |||||||||||||||||
| Removal Costs [Member] | Houston Electric [Member] | ||||||||||||||||||||
| Regulatory liabilities | 275 | 275 | 285 | |||||||||||||||||
| Removal Costs [Member] | CERC Corp [Member] | ||||||||||||||||||||
| Regulatory liabilities | 612 | 612 | 593 | |||||||||||||||||
| Other Regulatory Assets (Liabilities) [Member] | ||||||||||||||||||||
| Regulatory liabilities | 257 | 257 | 232 | |||||||||||||||||
| Other Regulatory Assets (Liabilities) [Member] | Houston Electric [Member] | ||||||||||||||||||||
| Regulatory liabilities | 132 | 132 | 116 | |||||||||||||||||
| Other Regulatory Assets (Liabilities) [Member] | CERC Corp [Member] | ||||||||||||||||||||
| Regulatory liabilities | 125 | 125 | 116 | |||||||||||||||||
| Natural Gas Distribution [Member] | Pension and Other Postretirement Plans Costs [Member] | ||||||||||||||||||||
| Remaining amounts of regulatory assets for which no return on investment during recovery period is provided | $ 4 | $ 4 | $ 7 | |||||||||||||||||
| ||||||||||||||||||||
| X | ||||||||||
- Definition Amount of allowed equity return on the true-up balance that was recognized in the period No definition available.
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| X | ||||||||||
- Definition Represents the balance of the allowed return on equity that has been deferred and recorded on the balance sheet No definition available.
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| X | ||||||||||
- Definition The net amount of all regulatory assets less all regulatory liabilities as of the end of the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The amount for the individual regulatory current liability as itemized in a table of regulatory current liabilities as of the end of the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Remaining balance of regulatory assets for which no return on investment during recovery is provided. In some cases, a regulator may permit an enterprise to include a cost that would be charged to expense by an unregulated enterprise as an allowable cost over a period of time by amortizing that cost for rate-making purposes, but the regulator does not include the unrecovered amount in the rate base. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Carrying value of the regulatory asset that represents capitalized stranded costs that have been securitized (financed with debt) and are expected to be recoverable through a transition charge after one year (or beyond the operating cycle if longer). A transition charge is a charge approved by a regulator that allows deregulated utilities to recover investments in certain assets, such as power plants, over a transition period leading into a deregulated market. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Unamortized Loss on Reacquired Debt is the loss incurred upon reacquisition or refinancing of debt, is treated as a deferred charge and amortized over the life of the new debt issued. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Derivative Instruments Derivatives and Hedging (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
Oct. 31, 2018 |
Dec. 31, 2017 |
||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Weather hedges term | 10 years | ||||||||
| Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Recognized gain (loss) on weather hedges | [1] | $ 0 | $ 0 | $ (4) | $ 1 | ||||
| 2018 to 2019 [Member] | Natural Gas Distribution [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Weather hedge bilateral cap amount | 9 | ||||||||
| 2018 to 2019 [Member] | Electric Transmission and Distribution [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Weather hedge bilateral cap amount | 8 | ||||||||
| 2018 to 2019 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Electric Transmission and Distribution [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Recognized gain (loss) on weather hedges | 0 | 0 | 0 | 0 | |||||
| 2017 to 2018 [Member] | Natural Gas Distribution [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Weather hedge bilateral cap amount | 8 | ||||||||
| 2017 to 2018 [Member] | Electric Transmission and Distribution [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Weather hedge bilateral cap amount | 9 | ||||||||
| 2017 to 2018 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Electric Transmission and Distribution [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Recognized gain (loss) on weather hedges | 0 | 0 | (4) | 0 | |||||
| 2016 to 2017 [Member] | Electric Transmission and Distribution [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Weather hedge bilateral cap amount | 9 | ||||||||
| 2016 to 2017 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Electric Transmission and Distribution [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Recognized gain (loss) on weather hedges | 0 | 0 | 0 | 1 | |||||
| Houston Electric [Member] | Interest Rate Contract [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Aggregate notional amount | 100 | 100 | |||||||
| CERC Corp [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Recognized gain (loss) on weather hedges | [1] | 0 | 0 | 0 | 0 | ||||
| CERC Corp [Member] | 2018 to 2019 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Natural Gas Distribution [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Recognized gain (loss) on weather hedges | 0 | 0 | 0 | 0 | |||||
| CERC Corp [Member] | 2017 to 2018 [Member] | Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member] | Natural Gas Distribution [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Recognized gain (loss) on weather hedges | 0 | $ 0 | 0 | $ 0 | |||||
| Not Designated as Hedging Instrument, Economic Hedge [Member] | Interest Rate Contract [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Aggregate notional amount | $ 200 | $ 200 | $ 0 | ||||||
| Cash Flow Hedging [Member] | Houston Electric [Member] | Interest Rate Contract [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Aggregate notional amount | $ 0 | ||||||||
| Cash Flow Hedging [Member] | Subsequent Event [Member] | Houston Electric [Member] | Interest Rate Contract [Member] | |||||||||
| Derivatives, Fair Value [Line Items] | |||||||||
| Aggregate notional amount | $ 100 | ||||||||
| |||||||||
| X | ||||||||||
- Definition Represents amount of bilateral cap related to weather hedges. No definition available.
|
| X | ||||||||||
- Definition Period of time used as the basis for weather hedges entered into by the company. No definition available.
|
| X | ||||||||||
- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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Derivative Instruments Summary of Derivative Activity (Details) $ in Millions |
3 Months Ended | 9 Months Ended | 12 Months Ended | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Sep. 30, 2018
USD ($)
|
Sep. 30, 2017
USD ($)
|
Sep. 30, 2018
USD ($)
Bcf
|
Sep. 30, 2017
USD ($)
|
Dec. 31, 2017
USD ($)
Bcf
|
||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | $ 164 | $ 164 | $ 218 | |||||||||||||||||||
| Derivative Liabilities Fair Value | 795 | 795 | 775 | |||||||||||||||||||
| Derivative Asset | 39 | 39 | 80 | |||||||||||||||||||
| Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item | 1 | 1 | 14 | |||||||||||||||||||
| Total amounts presented in the statements of income in which the effects of hedges are recorded | [1] | 864 | $ 832 | 2,927 | $ 2,843 | |||||||||||||||||
| Gain (loss) on derivative instruments not designated as hedging instruments | (42) | (6) | (246) | 103 | ||||||||||||||||||
| Net deferred gain (loss) from cash flow hedges (net of tax) | 3 | (2) | 6 | (3) | ||||||||||||||||||
| Aggregate fair value of derivatives containing material adverse change provisions in a net liability position | 2 | 2 | 2 | |||||||||||||||||||
| Fair value of collateral already posted | 0 | 0 | 0 | |||||||||||||||||||
| Additional collateral required to be posted if credit risk contingent features triggered | 1 | 1 | 2 | |||||||||||||||||||
| Interest Rate Contract [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Net deferred gain (loss) from cash flow hedges (net of tax) | [2] | 0 | (1) | (1) | (1) | |||||||||||||||||
| Interest Rate Contract [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | 1 | $ 1 | $ 1 | |||||||||||||||||||
| Energy Related Derivative [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative gross volume notional amount (in Bcf) | Bcf | 1,865 | 1,795 | ||||||||||||||||||||
| Net amount presented in the consolidated balance sheets | [3] | 72 | $ 72 | $ 130 | ||||||||||||||||||
| Gross Amounts Recognized | [4] | 51 | 51 | 111 | ||||||||||||||||||
| Gross Amounts Offset in the Consolidated Balance Sheets | 21 | 21 | 19 | |||||||||||||||||||
| Energy Related Derivative [Member] | Current Assets [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Asset | [3] | 73 | 73 | 110 | ||||||||||||||||||
| Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item | 1 | 1 | 14 | |||||||||||||||||||
| Gross Amounts Recognized | [4] | 107 | 107 | 165 | ||||||||||||||||||
| Gross Amounts Offset | (34) | (34) | (55) | |||||||||||||||||||
| Energy Related Derivative [Member] | Other Assets [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Asset | [3] | 38 | 38 | 44 | ||||||||||||||||||
| Gross Amounts Recognized | [4] | 54 | 54 | 53 | ||||||||||||||||||
| Gross Amounts Offset | (16) | (16) | (9) | |||||||||||||||||||
| Energy Related Derivative [Member] | Current Liabilities [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Gross Amounts Recognized | [4] | (77) | (77) | (83) | ||||||||||||||||||
| Gross Amounts Offset | 44 | 44 | 63 | |||||||||||||||||||
| Derivative Liability | [3] | (33) | (33) | (20) | ||||||||||||||||||
| Energy Related Derivative [Member] | Other Liabilities [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Gross Amounts Recognized | [4] | (33) | (33) | (24) | ||||||||||||||||||
| Gross Amounts Offset | 27 | 27 | 20 | |||||||||||||||||||
| Derivative Liability | [3] | (6) | $ (6) | $ (4) | ||||||||||||||||||
| Energy Related Derivative [Member] | Long [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative gross volume notional amount (in Bcf) | Bcf | 310 | 224 | ||||||||||||||||||||
| IDS Derivative [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | 0 | $ 0 | $ 0 | |||||||||||||||||||
| Derivative Liabilities Fair Value | 685 | 685 | 668 | |||||||||||||||||||
| Houston Electric [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | 3 | 3 | 0 | |||||||||||||||||||
| Derivative Liabilities Fair Value | 0 | 0 | 0 | |||||||||||||||||||
| Net deferred gain (loss) from cash flow hedges (net of tax) | 3 | 0 | 7 | (1) | ||||||||||||||||||
| Houston Electric [Member] | Interest Rate Contract [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Net deferred gain (loss) from cash flow hedges (net of tax) | [2] | 3 | 0 | 7 | (1) | |||||||||||||||||
| CERC Corp [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | 161 | 161 | 218 | |||||||||||||||||||
| Derivative Liabilities Fair Value | 110 | 110 | 107 | |||||||||||||||||||
| Total amounts presented in the statements of income in which the effects of hedges are recorded | 864 | 832 | 2,927 | 2,843 | ||||||||||||||||||
| Gain (loss) on derivative instruments not designated as hedging instruments | 2 | 30 | 70 | 162 | ||||||||||||||||||
| Net deferred gain (loss) from cash flow hedges (net of tax) | 0 | (1) | 0 | (1) | ||||||||||||||||||
| CERC Corp [Member] | Interest Rate Contract [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Net deferred gain (loss) from cash flow hedges (net of tax) | [2] | 0 | (1) | 0 | (1) | |||||||||||||||||
| CERC Corp [Member] | Energy Related Derivative [Member] | Not Designated as Hedging Instrument [Member] | Current Assets [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | [5],[6],[7] | 76 | 76 | 114 | ||||||||||||||||||
| Derivative Liabilities Fair Value | [5],[6],[7] | 3 | 3 | 4 | ||||||||||||||||||
| CERC Corp [Member] | Energy Related Derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Assets [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | [5],[6],[7] | 38 | 38 | 44 | ||||||||||||||||||
| Derivative Liabilities Fair Value | [5],[6],[7] | 0 | 0 | 0 | ||||||||||||||||||
| CERC Corp [Member] | Energy Related Derivative [Member] | Not Designated as Hedging Instrument [Member] | Current Liabilities [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | [5],[6],[7] | 31 | 31 | 38 | ||||||||||||||||||
| Derivative Liabilities Fair Value | [5],[6],[7] | 72 | 72 | 78 | ||||||||||||||||||
| CERC Corp [Member] | Energy Related Derivative [Member] | Not Designated as Hedging Instrument [Member] | Other Liabilities [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | [5],[6],[7] | 16 | 16 | 9 | ||||||||||||||||||
| Derivative Liabilities Fair Value | [5],[6],[7] | 33 | 33 | 24 | ||||||||||||||||||
| Cash Flow Hedging [Member] | Houston Electric [Member] | Interest Rate Contract [Member] | Designated as Fair Value Hedge [Member] | Current Assets [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | 3 | 3 | 0 | |||||||||||||||||||
| Derivative Liabilities Fair Value | 0 | 0 | 0 | |||||||||||||||||||
| Fair Value Hedging [Member] | Energy Related Derivative [Member] | Current Assets [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Asset | 39 | 39 | 80 | |||||||||||||||||||
| Fair Value Hedging [Member] | CERC Corp [Member] | Energy Related Derivative [Member] | Designated as Fair Value Hedge [Member] | Current Liabilities [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Derivative Assets Fair Value | [5],[6],[7] | 0 | 0 | 13 | ||||||||||||||||||
| Derivative Liabilities Fair Value | [5],[6],[7] | 2 | 2 | $ 1 | ||||||||||||||||||
| Gains (Losses) in Revenue [Member] | CERC Corp [Member] | Energy Related Derivative [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Gain (loss) on derivative instruments not designated as hedging instruments | 2 | 30 | 70 | 162 | ||||||||||||||||||
| Non-utility Natural Gas Expense [Member] | Fair Value Hedging [Member] | Energy Related Derivative [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Change in unrealized gain (loss) on fair value hedging instruments | [1] | 1 | 4 | (13) | (10) | |||||||||||||||||
| Amounts excluded from effectiveness testing recognized in earnings immediately (1) | [1],[8] | 6 | (9) | (73) | (93) | |||||||||||||||||
| Non-utility Natural Gas Expense [Member] | Fair Value Hedging [Member] | Energy Related Derivative [Member] | Designated as Fair Value Hedge [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Change in unrealized gain (loss) on fair value hedging instruments | [1] | (1) | (4) | 13 | 10 | |||||||||||||||||
| Gains (Losses) in Other Income (Expense) [Member] | IDS Derivative [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Gain (loss) on derivative instruments not designated as hedging instruments | (44) | (36) | (316) | (59) | ||||||||||||||||||
| Gains (Losses) in Interest and other finance charges [Member] | Interest Rate Contract [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Gain (loss) on derivative instruments not designated as hedging instruments | 0 | 0 | 0 | 0 | ||||||||||||||||||
| Gains (Losses) in Interest and other finance charges [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member] | ||||||||||||||||||||||
| Derivatives, Fair Value [Line Items] | ||||||||||||||||||||||
| Gain (loss) reclassified from accumulated OCI into income | $ 1 | $ (1) | $ 1 | $ (1) | ||||||||||||||||||
| ||||||||||||||||||||||
| X | ||||||||||
- Definition Total of gross amounts offset, net. No definition available.
|
| X | ||||||||||
- Definition The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount as of the balance sheet date of the unamortized adjustment to the carrying value of an interest-bearing hedged item made under an effective fair value hedge that is amortized upon discontinuation of the fair value hedge. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and elected not to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, and obligation to return cash collateral under master netting arrangements. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value of the assets less the liabilities of a derivative or group of derivatives. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, and right to receive cash collateral under master netting arrangements. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and elected not to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Nominal volume used to calculate payments on a derivative instrument. No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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| X | ||||||||||
- Definition Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair Value Measurements (Details) $ in Millions |
3 Months Ended | 9 Months Ended | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Sep. 30, 2018
USD ($)
|
Sep. 30, 2017
USD ($)
|
Sep. 30, 2018
USD ($)
|
Sep. 30, 2017
USD ($)
|
Dec. 31, 2017
USD ($)
|
||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] | ||||||||||||||||||
| Financial Liabilities Fair Value Disclosure | $ 724 | $ 724 | $ 692 | |||||||||||||||
| Assets | ||||||||||||||||||
| Derivative assets | 39 | 39 | 80 | |||||||||||||||
| Assets, Fair Value Disclosure | 815 | 815 | 1,199 | |||||||||||||||
| Total derivative assets, netting adjustment | [1] | (50) | (50) | (64) | ||||||||||||||
| Liabilities | ||||||||||||||||||
| Total derivative liabilities, netting adjustment | [1] | (71) | (71) | (83) | ||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||||||||||||||||||
| Beginning balance | (628) | $ (712) | (622) | $ (704) | ||||||||||||||
| Total gains (losses) | 1 | (38) | 4 | (38) | ||||||||||||||
| Total settlements | (1) | (1) | (36) | (5) | ||||||||||||||
| Transfers into Level 3 | 0 | 7 | (2) | 9 | ||||||||||||||
| Transfers out of Level 3 (1) | [2] | 650 | (6) | 678 | (12) | |||||||||||||
| Ending balance (2) | [3] | 22 | (750) | 22 | (750) | |||||||||||||
| The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date: | 11 | (36) | 9 | (42) | ||||||||||||||
| Carrying Amount [Member] | ||||||||||||||||||
| Estimated Fair Value of Financial Instruments | ||||||||||||||||||
| Long-term debt, including current maturities | [4] | 7,758 | 7,758 | 8,679 | ||||||||||||||
| Fair Value [Member] | ||||||||||||||||||
| Estimated Fair Value of Financial Instruments | ||||||||||||||||||
| Long-term debt, including current maturities | [4] | 7,888 | 7,888 | 9,220 | ||||||||||||||
| Energy Related Derivative [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative fair value offsets, net | 21 | 21 | 19 | |||||||||||||||
| Fair Value, Inputs, Level 1 [Member] | ||||||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] | ||||||||||||||||||
| Financial Liabilities Fair Value Disclosure | 0 | 0 | 0 | |||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 704 | 704 | 1,045 | |||||||||||||||
| Fair Value, Inputs, Level 2 [Member] | ||||||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] | ||||||||||||||||||
| Financial Liabilities Fair Value Disclosure | 790 | 790 | 96 | |||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 134 | 134 | 161 | |||||||||||||||
| Fair Value, Inputs, Level 3 [Member] | ||||||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] | ||||||||||||||||||
| Financial Liabilities Fair Value Disclosure | 5 | 5 | 679 | |||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 27 | $ 27 | 57 | |||||||||||||||
| Fair Value, Inputs, Level 3 [Member] | Forward Contracts [Member] | Minimum [Member] | ||||||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] | ||||||||||||||||||
| Fair value inputs (price per MMBtu) | 1.28 | |||||||||||||||||
| Fair Value, Inputs, Level 3 [Member] | Forward Contracts [Member] | Maximum [Member] | ||||||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] | ||||||||||||||||||
| Fair value inputs (price per MMBtu) | 6.88 | |||||||||||||||||
| Fair Value, Measurements, Recurring [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Corporate equities | 630 | $ 630 | 963 | |||||||||||||||
| Investments, including money market funds (2) | [5] | 70 | 70 | 68 | ||||||||||||||
| Hedged portion of natural gas inventory | 1 | 1 | 14 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative assets | 3 | 3 | 0 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Energy Related Derivative [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset, netting adjustment | [1],[6] | (50) | (50) | (64) | ||||||||||||||
| Derivative assets | [6] | 111 | 111 | 154 | ||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liabilities, netting adjustment | [1],[6] | (71) | (71) | (83) | ||||||||||||||
| Derivative liabilities | [6] | 39 | 39 | 24 | ||||||||||||||
| Fair Value, Measurements, Recurring [Member] | IDS Derivative [Member] | ||||||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liabilities, netting adjustment | [1] | 0 | 0 | 0 | ||||||||||||||
| Derivative liabilities | 685 | 685 | 668 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Corporate equities | 630 | 630 | 963 | |||||||||||||||
| Investments, including money market funds (2) | [5] | 70 | 70 | 68 | ||||||||||||||
| Hedged portion of natural gas inventory | 1 | 1 | 14 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Interest Rate Contract [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | 3 | 3 | 0 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Energy Related Derivative [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | [6] | 0 | 0 | 0 | ||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liability | [6] | 0 | 0 | 0 | ||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | IDS Derivative [Member] | ||||||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liability | 0 | 0 | 0 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Corporate equities | 0 | 0 | 0 | |||||||||||||||
| Investments, including money market funds (2) | [5] | 0 | 0 | 0 | ||||||||||||||
| Hedged portion of natural gas inventory | 0 | 0 | 0 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Contract [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | 0 | 0 | 0 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Energy Related Derivative [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | [6] | 134 | 134 | 161 | ||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liability | [6] | 105 | 105 | 96 | ||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | IDS Derivative [Member] | ||||||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liability | 685 | 685 | 0 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Corporate equities | 0 | 0 | 0 | |||||||||||||||
| Investments, including money market funds (2) | [5] | 0 | 0 | 0 | ||||||||||||||
| Hedged portion of natural gas inventory | 0 | 0 | 0 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest Rate Contract [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | 0 | 0 | 0 | |||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Energy Related Derivative [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | [6] | 27 | 27 | 57 | ||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liability | [6] | 5 | 5 | 11 | ||||||||||||||
| Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | IDS Derivative [Member] | ||||||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liability | 0 | 0 | 668 | |||||||||||||||
| CERC Corp [Member] | ||||||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] | ||||||||||||||||||
| Financial Liabilities Fair Value Disclosure | 39 | 39 | 24 | |||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 125 | 125 | 182 | |||||||||||||||
| Total derivative assets, netting adjustment | [1] | (50) | (50) | (64) | ||||||||||||||
| Liabilities | ||||||||||||||||||
| Total derivative liabilities, netting adjustment | [1] | (71) | (71) | (83) | ||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||||||||||||||||||
| Beginning balance | 13 | 28 | 46 | 13 | ||||||||||||||
| Total gains (losses) | 1 | (2) | 4 | 21 | ||||||||||||||
| Total settlements | (1) | (1) | (36) | (5) | ||||||||||||||
| Transfers into Level 3 | 0 | 7 | (2) | 9 | ||||||||||||||
| Transfers out of Level 3 (1) | [2] | 9 | (6) | 10 | (12) | |||||||||||||
| Ending balance (2) | [3] | 22 | 26 | 22 | 26 | |||||||||||||
| The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date: | 11 | $ 0 | 9 | $ 17 | ||||||||||||||
| CERC Corp [Member] | Carrying Amount [Member] | ||||||||||||||||||
| Estimated Fair Value of Financial Instruments | ||||||||||||||||||
| Long-term debt, including current maturities | 2,257 | 2,257 | 2,457 | |||||||||||||||
| CERC Corp [Member] | Fair Value [Member] | ||||||||||||||||||
| Estimated Fair Value of Financial Instruments | ||||||||||||||||||
| Long-term debt, including current maturities | 2,367 | 2,367 | 2,708 | |||||||||||||||
| CERC Corp [Member] | Fair Value, Inputs, Level 1 [Member] | ||||||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] | ||||||||||||||||||
| Financial Liabilities Fair Value Disclosure | 0 | 0 | 0 | |||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 14 | 14 | 28 | |||||||||||||||
| CERC Corp [Member] | Fair Value, Inputs, Level 2 [Member] | ||||||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] | ||||||||||||||||||
| Financial Liabilities Fair Value Disclosure | 105 | 105 | 96 | |||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 134 | 134 | 161 | |||||||||||||||
| CERC Corp [Member] | Fair Value, Inputs, Level 3 [Member] | ||||||||||||||||||
| Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] | ||||||||||||||||||
| Financial Liabilities Fair Value Disclosure | 5 | 5 | 11 | |||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 27 | 27 | 57 | |||||||||||||||
| CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Corporate equities | 3 | 3 | 3 | |||||||||||||||
| Investments, including money market funds (2) | [5] | 10 | 10 | 11 | ||||||||||||||
| Hedged portion of natural gas inventory | 1 | 1 | 14 | |||||||||||||||
| CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Energy Related Derivative [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset, netting adjustment | [1],[6] | (50) | (50) | (64) | ||||||||||||||
| Derivative assets | [6] | 111 | 111 | 154 | ||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liabilities, netting adjustment | [1],[6] | (71) | (71) | (83) | ||||||||||||||
| Derivative liabilities | [6] | 39 | 39 | 24 | ||||||||||||||
| CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Corporate equities | 3 | 3 | 3 | |||||||||||||||
| Investments, including money market funds (2) | [5] | 10 | 10 | 11 | ||||||||||||||
| Hedged portion of natural gas inventory | 1 | 1 | 14 | |||||||||||||||
| CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Energy Related Derivative [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | [6] | 0 | 0 | 0 | ||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liability | [6] | 0 | 0 | 0 | ||||||||||||||
| CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Corporate equities | 0 | 0 | 0 | |||||||||||||||
| Investments, including money market funds (2) | [5] | 0 | 0 | 0 | ||||||||||||||
| Hedged portion of natural gas inventory | 0 | 0 | 0 | |||||||||||||||
| CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Energy Related Derivative [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | [6] | 134 | 134 | 161 | ||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liability | [6] | 105 | 105 | 96 | ||||||||||||||
| CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Corporate equities | 0 | 0 | 0 | |||||||||||||||
| Investments, including money market funds (2) | [5] | 0 | 0 | 0 | ||||||||||||||
| Hedged portion of natural gas inventory | 0 | 0 | 0 | |||||||||||||||
| CERC Corp [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Energy Related Derivative [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | [6] | 27 | 27 | 57 | ||||||||||||||
| Liabilities | ||||||||||||||||||
| Derivative liability | [6] | 5 | 5 | 11 | ||||||||||||||
| Houston Electric [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 55 | 55 | 51 | |||||||||||||||
| Total derivative assets, netting adjustment | 0 | 0 | 0 | |||||||||||||||
| Houston Electric [Member] | Carrying Amount [Member] | ||||||||||||||||||
| Estimated Fair Value of Financial Instruments | ||||||||||||||||||
| Long-term debt, including current maturities | [4] | 4,782 | 4,782 | 4,753 | ||||||||||||||
| Houston Electric [Member] | Fair Value [Member] | ||||||||||||||||||
| Estimated Fair Value of Financial Instruments | ||||||||||||||||||
| Long-term debt, including current maturities | [4] | 4,813 | 4,813 | 5,034 | ||||||||||||||
| Houston Electric [Member] | Fair Value, Inputs, Level 1 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 55 | 55 | 51 | |||||||||||||||
| Houston Electric [Member] | Fair Value, Inputs, Level 2 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 0 | 0 | 0 | |||||||||||||||
| Houston Electric [Member] | Fair Value, Inputs, Level 3 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Assets, Fair Value Disclosure | 0 | 0 | 0 | |||||||||||||||
| Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Investments, including money market funds (2) | [5] | 52 | 52 | 51 | ||||||||||||||
| Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Contract [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative assets | 3 | 3 | 0 | |||||||||||||||
| Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Investments, including money market funds (2) | [5] | 52 | 52 | 51 | ||||||||||||||
| Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Interest Rate Contract [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | 3 | 3 | 0 | |||||||||||||||
| Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Investments, including money market funds (2) | [5] | 0 | 0 | 0 | ||||||||||||||
| Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Contract [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | 0 | 0 | 0 | |||||||||||||||
| Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Investments, including money market funds (2) | [5] | 0 | 0 | 0 | ||||||||||||||
| Houston Electric [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest Rate Contract [Member] | ||||||||||||||||||
| Assets | ||||||||||||||||||
| Derivative asset | $ 0 | $ 0 | $ 0 | |||||||||||||||
| ||||||||||||||||||
| X | ||||||||||
- Definition Total of gross amounts offset, net. No definition available.
|
| X | ||||||||||
- Definition This element represents a certain statement of financial position asset caption which represents a class of assets, or which may include an individual asset, measured at fair value on a recurring basis. No definition available.
|
| X | ||||||||||
- Definition Fair value inputs used for valuing physical forward contracts using a discounted cash flow model, including illiquid forward price curve locations. No definition available.
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and elected not to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, and obligation to return cash collateral under master netting arrangements. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, and right to receive cash collateral under master netting arrangements. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and elected not to be offset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Amount of unrealized (holding) gain (loss) which is included in the statement of income (or changes in net assets) related to those assets still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Fair value of all derivative assets designated as fair value hedging instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- Definition Amount of gain (loss) recognized in the income statement of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of settlements of financial instrument classified as a derivative asset (liability) after deduction of derivative liability, measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of transfers of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset) into level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of transfers of financial instrument classified as derivative asset (liability) after deduction of derivative liability (asset) out of level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Fair value of financial instrument classified as derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities. No definition available.
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- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. No definition available.
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Unconsolidated Affiliate (CenterPoint Energy and CERC) (Details) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 9 Months Ended | ||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 04, 2018 |
Dec. 31, 2017 |
|||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Preferred units – unconsolidated affiliate | $ 363 | $ 363 | $ 363 | |||||||||||||||||||||||||||||||
| Percentage of sales that trigger right of first refusal | 5.00% | |||||||||||||||||||||||||||||||||
| Enable Distributions [Abstract] | ||||||||||||||||||||||||||||||||||
| Total distributions received from Enable | 83 | $ 83 | $ 250 | $ 250 | ||||||||||||||||||||||||||||||
| Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) [Abstract] | ||||||||||||||||||||||||||||||||||
| Equity in earnings of unconsolidated affiliate, net | 81 | 68 | 208 | 199 | ||||||||||||||||||||||||||||||
| Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract] | ||||||||||||||||||||||||||||||||||
| CenterPoint Energy’s equity method investment in Enable | 2,457 | 2,457 | 2,472 | |||||||||||||||||||||||||||||||
| CERC Corp [Member] | ||||||||||||||||||||||||||||||||||
| Investment in unconsolidated affiliate - discontinued operations | 0 | 0 | 2,472 | |||||||||||||||||||||||||||||||
| Deferred income taxes, net - discontinued operations | 0 | 0 | 927 | |||||||||||||||||||||||||||||||
| Contribution from parent | 600 | 0 | 600 | 38 | ||||||||||||||||||||||||||||||
| Enable Distributions [Abstract] | ||||||||||||||||||||||||||||||||||
| Total distributions received from Enable | [1] | 74 | 74 | 223 | 223 | |||||||||||||||||||||||||||||
| Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract] | ||||||||||||||||||||||||||||||||||
| Income tax expense | 13 | 26 | 44 | 75 | ||||||||||||||||||||||||||||||
| Income from discontinued operations (net of tax of $13, $26, $44 and $75, respectively) | $ 44 | 42 | $ 140 | 124 | ||||||||||||||||||||||||||||||
| OGE [Member] | ||||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Percentage of sales that trigger right of first refusal | 5.00% | |||||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | ||||||||||||||||||||||||||||||||||
| Enable Partnership Interest [Abstract] | ||||||||||||||||||||||||||||||||||
| Ownership percentage of equity method investment | [2],[3] | 54.00% | 54.00% | |||||||||||||||||||||||||||||||
| Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) [Abstract] | ||||||||||||||||||||||||||||||||||
| Operating revenues | $ 928 | 705 | $ 2,481 | 1,997 | ||||||||||||||||||||||||||||||
| Cost of sales, excluding depreciation and amortization | 516 | 349 | 1,335 | 936 | ||||||||||||||||||||||||||||||
| Depreciation and amortization | 100 | 90 | 292 | 267 | ||||||||||||||||||||||||||||||
| Operating income | 171 | 137 | 436 | 399 | ||||||||||||||||||||||||||||||
| Net income attributable to Enable common units | 129 | 104 | 320 | 301 | ||||||||||||||||||||||||||||||
| CenterPoint Energy’s interest | 70 | 56 | 173 | 163 | ||||||||||||||||||||||||||||||
| Basis difference amortization (1) | [4] | 11 | 12 | 35 | 36 | |||||||||||||||||||||||||||||
| Equity in earnings of unconsolidated affiliate, net | 81 | 68 | $ 208 | 199 | ||||||||||||||||||||||||||||||
| Basis difference amortization period | 31 years | |||||||||||||||||||||||||||||||||
| Equity Method Investment, Summarized Financial Information, Assets and Liabilities [Abstract] | ||||||||||||||||||||||||||||||||||
| Current assets | 481 | $ 481 | 416 | |||||||||||||||||||||||||||||||
| Non-current assets | 11,454 | 11,454 | 11,177 | |||||||||||||||||||||||||||||||
| Current liabilities | 1,403 | 1,403 | 1,279 | |||||||||||||||||||||||||||||||
| Non-current liabilities | 2,964 | 2,964 | 2,660 | |||||||||||||||||||||||||||||||
| Non-controlling interest | 11 | 11 | 12 | |||||||||||||||||||||||||||||||
| Preferred equity | 362 | 362 | 362 | |||||||||||||||||||||||||||||||
| Enable partners’ equity | 7,195 | 7,195 | 7,280 | |||||||||||||||||||||||||||||||
| Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract] | ||||||||||||||||||||||||||||||||||
| CenterPoint Energy’s ownership interest in Enable partners’ equity | 3,883 | 3,883 | 3,935 | |||||||||||||||||||||||||||||||
| CenterPoint Energy’s basis difference | (1,426) | (1,426) | (1,463) | |||||||||||||||||||||||||||||||
| CenterPoint Energy’s equity method investment in Enable | 2,457 | 2,457 | 2,472 | |||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | Common Units [Member] | ||||||||||||||||||||||||||||||||||
| Enable Distributions [Abstract] | ||||||||||||||||||||||||||||||||||
| Distributions received from Enable equity method investment | [5] | 74 | 74 | 223 | 223 | |||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | Series A Preferred Units [Member] | ||||||||||||||||||||||||||||||||||
| Enable Distributions [Abstract] | ||||||||||||||||||||||||||||||||||
| Distributions received from Enable cost method investment | [6] | $ 9 | 9 | $ 27 | 27 | |||||||||||||||||||||||||||||
| Common Units [Member] | Enable Midstream Partners [Member] | ||||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Limited partner interest units held | [3] | 233,856,623 | 233,856,623 | |||||||||||||||||||||||||||||||
| Series A Preferred Units [Member] | Enable Midstream Partners [Member] | ||||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Preferred Units Held | [3],[7] | 14,520,000 | 14,520,000 | |||||||||||||||||||||||||||||||
| Transitional Service [Member] | Enable Midstream Partners [Member] | ||||||||||||||||||||||||||||||||||
| Related Party Transaction, Other Revenues from Transactions with Related Party | [8] | $ 1 | 0 | $ 4 | 3 | |||||||||||||||||||||||||||||
| Transactions with Enable [Abstract] | ||||||||||||||||||||||||||||||||||
| Accounts receivable for amounts billed for transition services (CenterPoint Energy) | 3 | 3 | 1 | |||||||||||||||||||||||||||||||
| Natural Gas Expenses [Member] | Enable Midstream Partners [Member] | ||||||||||||||||||||||||||||||||||
| Transactions with Enable [Abstract] | ||||||||||||||||||||||||||||||||||
| Natural gas expenses, including transportation and storage costs (CenterPoint Energy and CERC) | 23 | 23 | 89 | 80 | ||||||||||||||||||||||||||||||
| Accounts payable for natural gas purchases from Enable (CenterPoint Energy and CERC) | $ 8 | $ 8 | 13 | |||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | ||||||||||||||||||||||||||||||||||
| Enable Partnership Interest [Abstract] | ||||||||||||||||||||||||||||||||||
| Limited partner ownership interest | [2] | 100.00% | ||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Maximum incentive distribution right | 50.00% | |||||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | OGE [Member] | ||||||||||||||||||||||||||||||||||
| Enable Partnership Interest [Abstract] | ||||||||||||||||||||||||||||||||||
| Limited partner ownership interest | [2] | 25.60% | ||||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | Public unitholders [Member] | ||||||||||||||||||||||||||||||||||
| Enable Partnership Interest [Abstract] | ||||||||||||||||||||||||||||||||||
| Limited partner ownership interest | [2] | 20.40% | ||||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | Minimum [Member] | ||||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Incentive distribution per unit | $ 0.2875 | |||||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | Maximum [Member] | ||||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Incentive distribution per unit | $ 0.330625 | |||||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | Common Units [Member] | ||||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Limited partner interest units held | 433,216,156 | 433,216,156 | ||||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | Common Units [Member] | OGE [Member] | ||||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Limited partner interest units held | 110,982,805 | 110,982,805 | ||||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | Common Units [Member] | Public unitholders [Member] | ||||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Limited partner interest units held | 88,376,728 | 88,376,728 | ||||||||||||||||||||||||||||||||
| Enable GP, LLC [Member] | CenterPoint Energy [Member] | ||||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Management rights ownership percentage | [9],[10] | 50.00% | ||||||||||||||||||||||||||||||||
| Incentive distribution right | [10],[11] | 40.00% | ||||||||||||||||||||||||||||||||
| Enable GP, LLC [Member] | OGE [Member] | ||||||||||||||||||||||||||||||||||
| Enable Units [Abstract] | ||||||||||||||||||||||||||||||||||
| Management rights ownership percentage | [9] | 50.00% | ||||||||||||||||||||||||||||||||
| Incentive distribution right | [11] | 60.00% | ||||||||||||||||||||||||||||||||
| Enable Midstream Partners [Member] | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff [Member] | CERC Corp [Member] | ||||||||||||||||||||||||||||||||||
| Investment in unconsolidated affiliate - discontinued operations | $ 0 | [12] | $ 0 | [12] | $ 2,400 | $ 2,472 | [12] | |||||||||||||||||||||||||||
| Deferred income taxes, net - discontinued operations | $ 974 | |||||||||||||||||||||||||||||||||
| Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract] | ||||||||||||||||||||||||||||||||||
| Equity in earnings of unconsolidated affiliate, net | 57 | 68 | 184 | 199 | ||||||||||||||||||||||||||||||
| Income tax expense | 13 | 26 | 44 | 75 | ||||||||||||||||||||||||||||||
| Income from discontinued operations (net of tax of $13, $26, $44 and $75, respectively) | $ 44 | $ 42 | $ 140 | $ 124 | ||||||||||||||||||||||||||||||
| Common Units [Member] | Enable Midstream Partners [Member] | ||||||||||||||||||||||||||||||||||
| Enable Distributions [Abstract] | ||||||||||||||||||||||||||||||||||
| Enable common units distributions paid (per unit) | $ 0.318 | $ 0.954 | ||||||||||||||||||||||||||||||||
| Series A Preferred Units [Member] | Enable Midstream Partners [Member] | ||||||||||||||||||||||||||||||||||
| Enable Distributions [Abstract] | ||||||||||||||||||||||||||||||||||
| Enable common units distributions paid (per unit) | $ 0.625 | $ 1.875 | ||||||||||||||||||||||||||||||||
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- Definition Basis Difference Accretion Gain No definition available.
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- Definition Represents the basis difference amortization period in years No definition available.
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- Definition This item represents disclosure of the amount of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporation; these investments are accounted for under the cost method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities. No definition available.
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- Definition Enable Distributions [Abstract] No definition available.
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- Definition Enable Partnership Interest [Abstract] No definition available.
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- Definition Enable Units [Abstract] No definition available.
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- Definition This represents the basis difference of an equity method investment. No definition available.
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- Definition This represents the gross equity in earnings (losses) of equity method investment, excluding any basis difference. No definition available.
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- Definition Equity Method Investment, Ownership, Shares No definition available.
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- Definition The amount of the depreciation and amortization reported by an equity method investment of the entity. No definition available.
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- Definition The amount of operating income (loss) reported by an equity method investment of the entity. No definition available.
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- Definition Amount of preferred equity attributable to the equity method investment of the entity. No definition available.
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- Definition Maximum additional incentive right to the general partner with quarterly distribution per unit exceeding $0.330625 No definition available.
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- Definition Entity's interest in incentive distribution rights held by the general partner. No definition available.
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| X | ||||||||||
- Definition Represents the percentage of management rights in the general partner of Enable No definition available.
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| X | ||||||||||
- Definition Represents the number of Series A Preferred Units held as of the balance sheet date. No definition available.
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| X | ||||||||||
- Definition Sale of more than this percentage of aggregated common and subordinated units owned are subject to mutual rights of first offer and first refusal. No definition available.
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| X | ||||||||||
- Definition Represents the total amount of distributions received related to both equity method investments and cost method investments from Enable. No definition available.
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- Definition Transactions with Enable [Abstract] No definition available.
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| X | ||||||||||
- Definition Represents the number of shares owned of the variable interest entity as of the balance sheet date No definition available.
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- Definition Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition For an unclassified balance sheet, amount of receivables arising from transactions with related parties. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount classified as assets attributable to disposal group held for sale or disposed of. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount before tax of income (loss) from a discontinued operation. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount classified as deferred tax liabilities attributable to disposal group held for sale or disposed of. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Per unit of ownership amount of cash distributions paid to unit-holder of a limited partnership (LP). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Amount of distribution received from equity method investee for return on investment, classified as operating activities. Excludes distribution for return of investment, classified as investing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition The amount of the cost of sales reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of current assets reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of current liabilities reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of equity, excluding noncontrolling interest, attributable to the equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Amount of equity attributable to noncontrolling interests of an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of net income (loss) reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of noncurrent assets reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of noncurrent liabilities reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of revenue from sale of goods and services reduced by sales returns, allowances, and discounts reported by an equity method investment of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition This item represents the entity's ownership percentage in the investee multiplied by the investee's total equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Per-share or per-unit amount of incentive dividend declared and paid to managing member or general partner. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount after tax of income (loss) from a discontinued operation attributable to the parent. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The cash inflow from parent as a source of financing that is recorded as additional paid in capital. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Reflects the sum of all other revenue and income realized from sales and other transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party during the period. No definition available.
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| X | ||||||||||
- Definition Purchases during the period (excluding transactions that are eliminated in consolidated or combined financial statements) with related party. No definition available.
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| X | ||||||||||
- Definition Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Goodwill and Other Intangibles (CenterPoint Energy and CERC) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | 12 Months Ended | ||||
|---|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
Dec. 31, 2017 |
|||
| Goodwill [Line Items] | |||||||
| Goodwill | $ 867 | $ 867 | $ 867 | ||||
| Intangible assets gross carrying amount | 105 | 105 | 105 | ||||
| Intangible assets accumulated amortization | (38) | (38) | (31) | ||||
| Net intangible assets | 67 | 67 | 74 | ||||
| Amortization expense of intangible assets | 2 | $ 2 | 7 | $ 5 | |||
| Natural Gas Distribution [Member] | |||||||
| Goodwill [Line Items] | |||||||
| Goodwill | 746 | 746 | 746 | ||||
| Energy Services [Member] | |||||||
| Goodwill [Line Items] | |||||||
| Goodwill | [1] | 110 | 110 | 110 | |||
| Accumulated goodwill impairment charge recorded in 2012 | 252 | 252 | 252 | ||||
| Other Operations [Member] | |||||||
| Goodwill [Line Items] | |||||||
| Goodwill | 11 | $ 11 | $ 11 | ||||
| Customer Relationships [Member] | |||||||
| Goodwill [Line Items] | |||||||
| Intangible asset useful lives | 15 years | 15 years | |||||
| Intangible assets gross carrying amount | 86 | $ 86 | $ 86 | ||||
| Intangible assets accumulated amortization | (26) | (26) | (21) | ||||
| Net intangible assets | 60 | $ 60 | $ 65 | ||||
| Noncompete Agreements [Member] | |||||||
| Goodwill [Line Items] | |||||||
| Intangible asset useful lives | 4 years | 4 years | |||||
| Intangible assets gross carrying amount | 4 | $ 4 | $ 4 | ||||
| Intangible assets accumulated amortization | (2) | (2) | (2) | ||||
| Net intangible assets | 2 | 2 | 2 | ||||
| Other Intangible Assets [Member] | |||||||
| Goodwill [Line Items] | |||||||
| Intangible assets gross carrying amount | 15 | 15 | 15 | ||||
| Intangible assets accumulated amortization | (10) | (10) | (8) | ||||
| Net intangible assets | $ 5 | $ 5 | $ 7 | ||||
| |||||||
| X | ||||||||||
- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. No definition available.
|
| X | ||||||||||
- Definition Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) (Details) $ / shares in Units, $ in Millions |
9 Months Ended | |||||
|---|---|---|---|---|---|---|
|
Sep. 30, 2018
USD ($)
shares
$ / shares
|
Sep. 30, 2017
USD ($)
|
Jun. 14, 2018
$ / shares
shares
|
Jan. 31, 2018
$ / shares
|
Dec. 31, 2017
shares
|
Nov. 26, 2017
$ / shares
|
|
| Cash paid per share exchanged | $ / shares | $ 72.00 | |||||
| Distribution To ZENS holders | $ 398 | $ 0 | ||||
| Subordinated Debt ZENS [Member] | ||||||
| Principal amount of debt issued | 1,000 | |||||
| Outstanding debt balance | $ 828 | |||||
| Subordinated note cash exchangeable percentage of fair value | 95.00% | |||||
| Contingent principal amount outstanding | $ 98 | |||||
| AT&T To Acquire Time Warner [Member] | ||||||
| Distribution To ZENS holders | 382 | |||||
| Indexed debt – reduction | (95) | |||||
| Indexed debt securities derivative – reduction | (45) | |||||
| Loss on indexed debt securities | 242 | |||||
| Meredith to acquire Time [Member] | ||||||
| Distribution To ZENS holders | 16 | |||||
| Indexed debt – reduction | (4) | |||||
| Indexed debt securities derivative – reduction | (1) | |||||
| Loss on indexed debt securities | $ 11 | |||||
| AT&T Common [Member] | ||||||
| Balance of investment owned (in shares) | shares | 10,212,945 | |||||
| AT&T Common [Member] | Subordinated Debt ZENS [Member] | ||||||
| Number of shares referenced in exchangeable subordinated note | shares | 0.7185 | |||||
| AT&T Common [Member] | AT&T To Acquire Time Warner [Member] | ||||||
| Cash paid per share exchanged | $ / shares | $ 53.75 | |||||
| Fractional shares exchanged for each TW Common share held | shares | 1.437 | |||||
| Cash proceeds received for shares exchanged | $ 382 | |||||
| Total AT&T shares received in exchange for TW Common shares held | shares | 10,212,945 | |||||
| Charter Common [Member] | ||||||
| Balance of investment owned (in shares) | shares | 872,503 | 872,503 | ||||
| Charter Common [Member] | Subordinated Debt ZENS [Member] | ||||||
| Number of shares referenced in exchangeable subordinated note | shares | 0.061382 | 0.061382 | ||||
| Time Common [Member] | ||||||
| Balance of investment owned (in shares) | shares | 888,392 | |||||
| ZENS early exchange ratio | 100.00% | |||||
| Time Common [Member] | Subordinated Debt ZENS [Member] | ||||||
| Number of shares referenced in exchangeable subordinated note | shares | 0.0625 | |||||
| Time Common [Member] | Meredith to acquire Time [Member] | ||||||
| Cash paid per share exchanged | $ / shares | $ 18.50 | $ 18.50 | ||||
| Cash proceeds received for shares exchanged | $ 16 | |||||
| TW Common [Member] | ||||||
| Balance of investment owned (in shares) | shares | 7,107,130 | |||||
| TW Common [Member] | Subordinated Debt ZENS [Member] | ||||||
| Number of shares referenced in exchangeable subordinated note | shares | 0.5 | |||||
| X | ||||||||||
- Definition Amount of outstanding contingent principal under the zero premium exchangeable subordinated notes contract contingent principal clause. No definition available.
|
| X | ||||||||||
- Definition This represents a distribution to ZENS holders during the period in accordance with the terms of the ZENS. No definition available.
|
| X | ||||||||||
- Definition Represents the fractional shares exchanged for each TW Common share held. No definition available.
|
| X | ||||||||||
- Definition Number of shares attributable to each note and referenced in determining the fair value of the cash to be exchange at behest of note holder. No definition available.
|
| X | ||||||||||
- Definition Represents the amount of realized loss on indexed debt securities recognized in the period. No definition available.
|
| X | ||||||||||
- Definition Represents the amount that indexed debt was reduced as a result of remittance to ZENS note holders in accordance with the terms of the ZENS. No definition available.
|
| X | ||||||||||
- Definition Represents the amount of reduction in ZENS derivative obligation due to the partial settlement No definition available.
|
| X | ||||||||||
- Definition The percentage of the fair value of the referenced TW Common shares attributable to each note and the percentage of composite fair value each note can be exchanged for cash. No definition available.
|
| X | ||||||||||
- Definition Represents the total AT&T shares received in exchange for the TW Common held. No definition available.
|
| X | ||||||||||
- Definition Early exchange ratio on ZENS subordinated debt. No definition available.
|
| X | ||||||||||
- Definition Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination. No definition available.
|
| X | ||||||||||
- Definition Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Face (par) amount of debt instrument at time of issuance. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Balance held at close of period in number of shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The cash inflow associated with the sale, maturities, repayments and calls of securities classified as trading securities and held for investment purposes. Excludes proceeds from trading securities purchased and held principally for the purpose of selling them in the near term (thus held for only a short period of time). No definition available.
|
| X | ||||||||||
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Short-Term Borrowings and Long-term Debt (Details) |
9 Months Ended | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Oct. 05, 2018
USD ($)
|
Mar. 26, 2018
USD ($)
|
Feb. 28, 2018
USD ($)
|
Sep. 30, 2018
USD ($)
|
Dec. 31, 2017
USD ($)
|
|||||||||||||
| Short-term Debt [Line Items] | |||||||||||||||||
| Short-term borrowings | $ 0 | $ 39,000,000 | |||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Size of credit facility | 2,900,000,000 | 2,900,000,000 | |||||||||||||||
| Parent Company [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Size of credit facility | 1,700,000,000 | [1] | 1,700,000,000 | ||||||||||||||
| Temporary increased line of credit facility, maximum borrowing capacity | 3,300,000,000 | ||||||||||||||||
| Houston Electric [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Size of credit facility | 300,000,000 | 300,000,000 | |||||||||||||||
| General mortgage bonds used as collateral | 118,000,000 | 118,000,000 | |||||||||||||||
| CERC Corp [Member] | |||||||||||||||||
| Short-term Debt [Line Items] | |||||||||||||||||
| Short-term borrowings | 0 | 39,000,000 | |||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Size of credit facility | 900,000,000 | 900,000,000 | |||||||||||||||
| Revolving Credit Facility [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | 0 | 0 | |||||||||||||||
| Revolving Credit Facility [Member] | Parent Company [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | 0 | 0 | |||||||||||||||
| Revolving Credit Facility [Member] | Houston Electric [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | 0 | 0 | |||||||||||||||
| Revolving Credit Facility [Member] | CERC Corp [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | $ 0 | 0 | |||||||||||||||
| Line of Credit [Member] | Parent Company [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Percentage on limitation of debt to total capitalization under covenant | 65.00% | ||||||||||||||||
| Percentage on limitation of debt to total capitalization under covenant amended (in hundredths) | 70.00% | ||||||||||||||||
| Ratio of indebtedness to net capital | [2] | 0.475 | |||||||||||||||
| System restoration costs threshold for increase in permitted debt to EBITDA covenant ratio | $ 100,000,000 | ||||||||||||||||
| Consecutive period for system restoration costs to exceed $100 million (in months) | 12 | ||||||||||||||||
| Line of Credit [Member] | Parent Company [Member] | London Interbank Offered Rate (LIBOR) [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Basis spread on LIBOR | [3] | 1.25% | |||||||||||||||
| Line of Credit [Member] | Houston Electric [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Percentage on limitation of debt to total capitalization under covenant | [4] | 65.00% | |||||||||||||||
| Ratio of indebtedness to net capital | [2] | 0.507 | |||||||||||||||
| Line of Credit [Member] | Houston Electric [Member] | London Interbank Offered Rate (LIBOR) [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Basis spread on LIBOR | [3] | 1.125% | |||||||||||||||
| Line of Credit [Member] | CERC Corp [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Percentage on limitation of debt to total capitalization under covenant | 65.00% | ||||||||||||||||
| Ratio of indebtedness to net capital | [2] | 0.486 | |||||||||||||||
| Line of Credit [Member] | CERC Corp [Member] | London Interbank Offered Rate (LIBOR) [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Basis spread on LIBOR | [3] | 1.125% | |||||||||||||||
| Letter of Credit [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | $ 11,000,000 | 11,000,000 | |||||||||||||||
| Letter of Credit [Member] | Parent Company [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | 6,000,000 | 6,000,000 | |||||||||||||||
| Letter of Credit [Member] | Houston Electric [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | 4,000,000 | 4,000,000 | |||||||||||||||
| Letter of Credit [Member] | CERC Corp [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | 1,000,000 | 1,000,000 | |||||||||||||||
| Commercial Paper [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | 202,000,000 | 1,753,000,000 | |||||||||||||||
| Commercial Paper [Member] | Parent Company [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | $ 104,000,000 | $ 855,000,000 | |||||||||||||||
| Weighted average interest rate of debt | 2.42% | 1.88% | |||||||||||||||
| Commercial Paper [Member] | Houston Electric [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | $ 0 | $ 0 | |||||||||||||||
| Commercial Paper [Member] | CERC Corp [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Long-term line of credit | $ 98,000,000 | $ 898,000,000 | |||||||||||||||
| Weighted average interest rate of debt | 2.43% | 1.72% | |||||||||||||||
| General Mortgage Bonds Due 2048 [Member] | Houston Electric [Member] | |||||||||||||||||
| Debt Instruments [Abstract] | |||||||||||||||||
| Principal amount of debt issued | $ 400,000,000 | ||||||||||||||||
| Interest rate of debt issued | 3.95% | ||||||||||||||||
| Maturity date of debt issued | Mar. 01, 2048 | ||||||||||||||||
| Senior Notes Due 2023 [Member] | CERC Corp [Member] | |||||||||||||||||
| Debt Instruments [Abstract] | |||||||||||||||||
| Principal amount of debt issued | $ 300,000,000 | ||||||||||||||||
| Interest rate of debt issued | 3.55% | ||||||||||||||||
| Maturity date of debt issued | Apr. 01, 2023 | ||||||||||||||||
| Senior Notes Due 2028 [Member] | CERC Corp [Member] | |||||||||||||||||
| Debt Instruments [Abstract] | |||||||||||||||||
| Principal amount of debt issued | $ 300,000,000 | ||||||||||||||||
| Interest rate of debt issued | 4.00% | ||||||||||||||||
| Maturity date of debt issued | Apr. 01, 2028 | ||||||||||||||||
| Merger Agreement with Vectren [Member] | Parent Company [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Temporary increased line of credit facility, maximum borrowing capacity | $ 3,300,000,000 | ||||||||||||||||
| Merger Agreement with Vectren [Member] | Line of Credit [Member] | Parent Company [Member] | |||||||||||||||||
| Line of Credit Facility [Abstract] | |||||||||||||||||
| Percentage on limitation of debt to total capitalization under covenant amended (in hundredths) | [4],[5] | 75.00% | |||||||||||||||
| Subsequent Event [Member] | |||||||||||||||||
| Debt Instruments [Abstract] | |||||||||||||||||
| Principal amount of debt issued | $ 1,500,000,000 | ||||||||||||||||
| Subsequent Event [Member] | Senior Notes Due 2021 [Member] | |||||||||||||||||
| Debt Instruments [Abstract] | |||||||||||||||||
| Principal amount of debt issued | $ 500,000,000 | ||||||||||||||||
| Interest rate of debt issued | 3.60% | ||||||||||||||||
| Maturity date of debt issued | Nov. 01, 2021 | ||||||||||||||||
| Subsequent Event [Member] | Senior Notes Due 2024 [Member] | |||||||||||||||||
| Debt Instruments [Abstract] | |||||||||||||||||
| Principal amount of debt issued | $ 500,000,000 | ||||||||||||||||
| Interest rate of debt issued | 3.85% | ||||||||||||||||
| Maturity date of debt issued | Feb. 01, 2024 | ||||||||||||||||
| Subsequent Event [Member] | CNP Senior Notes Due 2028 [Member] | |||||||||||||||||
| Debt Instruments [Abstract] | |||||||||||||||||
| Principal amount of debt issued | $ 500,000,000 | ||||||||||||||||
| Interest rate of debt issued | 4.25% | ||||||||||||||||
| Maturity date of debt issued | Nov. 01, 2028 | ||||||||||||||||
| Product Financing Arrangement [Member] | |||||||||||||||||
| Short-term Debt [Line Items] | |||||||||||||||||
| Short-term borrowings | $ 0 | $ 39,000,000 | |||||||||||||||
| Senior Notes Redemption Period One [Member] | Subsequent Event [Member] | CNP Senior Notes [Member] | |||||||||||||||||
| Debt Instruments [Abstract] | |||||||||||||||||
| Debt instrument redemption price (percentage) | 101.00% | ||||||||||||||||
| Senior Notes Redemption Period Two [Member] | Subsequent Event [Member] | CNP Senior Notes [Member] | |||||||||||||||||
| Debt Instruments [Abstract] | |||||||||||||||||
| Debt instrument redemption price (percentage) | 101.00% | ||||||||||||||||
| |||||||||||||||||
| X | ||||||||||
- Definition Consecutive Period for System Restoration Costs to Exceed $100 million (in months) No definition available.
|
| X | ||||||||||
- Definition General mortgage bonds used as collateral No definition available.
|
| X | ||||||||||
- Definition Percentage on limitation of debt to total capitalization under covenant. No definition available.
|
| X | ||||||||||
- Definition Temporary increased percentage on limitation of debt to total capitalization under covenant (in hundredths) No definition available.
|
| X | ||||||||||
- Definition The minimum amount of estimated restoration cost in a calendar year in order for a temporary increase in debt to EBITDA covenant No definition available.
|
| X | ||||||||||
- Definition Pursuant to terms of the Merger agreement, the temporary increased maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. No definition available.
|
| X | ||||||||||
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. No definition available.
|
| X | ||||||||||
- Definition Face (par) amount of debt instrument at time of issuance. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Contractual interest rate for funds borrowed, under the debt agreement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Percentage price of original principal amount of debt at which debt can be redeemed by the issuer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Weighted average interest rate of debt outstanding. No definition available.
|
| X | ||||||||||
- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- References No definition available.
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- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Indebtedness divided by net capital. No definition available.
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| X | ||||||||||
- Definition Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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Income Taxes (Details) |
3 Months Ended | 9 Months Ended | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
||||||||||||||||
| Effective income tax rate | [1] | 24.00% | 37.00% | 26.00% | 36.00% | ||||||||||||||
| Federal statutory income tax rate | 21.00% | 35.00% | |||||||||||||||||
| Houston Electric [Member] | |||||||||||||||||||
| Effective income tax rate | [2] | 20.00% | 35.00% | 21.00% | 36.00% | ||||||||||||||
| CERC Corp [Member] | |||||||||||||||||||
| Effective income tax rate | 5.00% | [3] | 20.00% | [3] | 29.00% | [4] | 38.00% | [4] | |||||||||||
| Effective income tax rate - discontinued operations | [5] | 23.00% | 38.00% | 24.00% | 38.00% | ||||||||||||||
| State and Local Jurisdiction [Member] | |||||||||||||||||||
| Percentage impact to effective income tax rate | 5.00% | 7.00% | |||||||||||||||||
| State and Local Jurisdiction [Member] | CERC Corp [Member] | |||||||||||||||||||
| Percentage impact to effective income tax rate | 18.00% | 22.00% | |||||||||||||||||
| EDIT [Member] | |||||||||||||||||||
| Percentage impact to effective income tax rate | 5.00% | 4.00% | |||||||||||||||||
| EDIT [Member] | Houston Electric [Member] | |||||||||||||||||||
| Percentage impact to effective income tax rate | 2.00% | 2.00% | |||||||||||||||||
| EDIT [Member] | CERC Corp [Member] | |||||||||||||||||||
| Percentage impact to effective income tax rate | 15.00% | 20.00% | |||||||||||||||||
| |||||||||||||||||||
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- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to discontinued operations. No definition available.
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- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Percentage of the difference, between reported income tax expense (benefit) and the expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, that is attributable to tax exempt income, equity in earnings (loss) of an unconsolidated subsidiary, minority interest income (expense), tax holiday, disposition of a business, disposition of an asset, repatriation of foreign earnings, repatriation of foreign earnings jobs creation act of 2004, change in enacted tax rate, prior year income taxes, change in deferred tax asset valuation allowance, and other adjustments. No definition available.
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Commitments and Contingencies (Details) |
9 Months Ended |
|---|---|
|
Sep. 30, 2018
USD ($)
| |
| CERC Corp [Member] | Minnesota Service Territory [Member] | |
| Legal, Environmental and Other Matters | |
| Liability recorded for remediation of Minnesota sites | $ 7,000,000 |
| CERC Corp [Member] | Minnesota Service Territory [Member] | Minimum [Member] | |
| Legal, Environmental and Other Matters | |
| Estimated remediation costs for the Minnesota sites | $ 4,000,000 |
| Years to resolve contingency | 30 years |
| CERC Corp [Member] | Minnesota Service Territory [Member] | Maximum [Member] | |
| Legal, Environmental and Other Matters | |
| Estimated remediation costs for the Minnesota sites | $ 30,000,000 |
| Years to resolve contingency | 50 years |
| Natural Gas Supply Commitments [Member] | |
| Natural Gas Supply Commitments | |
| Remaining three months of 2018 | $ 88,000,000 |
| 2019 | 325,000,000 |
| 2020 | 303,000,000 |
| 2021 | 219,000,000 |
| 2022 | 183,000,000 |
| 2023 and beyond | 1,644,000,000 |
| Minnehaha Academy Gas Explosion [Member] | |
| Legal, Environmental and Other Matters | |
| Contested amount of fines imposed | $ 200,000 |
| X | ||||||||||
- Definition Contested amount of fines imposed by the Minnesota Office of Pipeline Safety. No definition available.
|
| X | ||||||||||
- Definition Estimate of the reasonably possible loss exposure at an individual site. No definition available.
|
| X | ||||||||||
- Definition This represents the estimated years necessary to resolve the contingency. No definition available.
|
| X | ||||||||||
- Definition Total costs accrued as of the balance sheet date for environmental loss contingencies. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Minimum amount of purchase arrangement maturing after the fifth fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments. No definition available.
|
| X | ||||||||||
- Definition Minimum amount of purchase arrangement maturing in the fifth fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments. No definition available.
|
| X | ||||||||||
- Definition Minimum amount of purchase arrangement maturing in the fourth fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments. No definition available.
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- Definition Minimum amount of purchase arrangement maturing in the second fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments. No definition available.
|
| X | ||||||||||
- Definition Minimum amount of purchase arrangement maturing in the third fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments. No definition available.
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- References No definition available.
|
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- Definition Minimum amount of purchase arrangement maturing in the remainder of the fiscal year following the latest fiscal year ended. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments. No definition available.
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Earnings Per Share (CenterPoint Energy) (Details) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
|
| Income available to common shareholders | $ 153 | $ 169 | $ 243 | $ 496 |
| Basic weighted average common shares outstanding | 431,554,000 | 431,026,000 | 431,437,000 | 430,939,000 |
| Plus: Incremental shares from assumed conversions: | ||||
| Diluted weighted average common shares | 434,891,000 | 434,086,000 | 434,774,000 | 433,999,000 |
| Basic earnings per common share | ||||
| Basic earnings per common share | $ 0.35 | $ 0.39 | $ 0.56 | $ 1.15 |
| Diluted earnings per common share | ||||
| Diluted earnings per common share | $ 0.35 | $ 0.39 | $ 0.56 | $ 1.14 |
| Restricted Stock [Member] | ||||
| Plus: Incremental shares from assumed conversions: | ||||
| Restricted stock | 3,337,000 | 3,060,000 | 3,337,000 | 3,060,000 |
| X | ||||||||||
- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
|
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- Definition The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
|
| X | ||||||||||
- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reportable Business Segments (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 04, 2018 |
Dec. 31, 2017 |
|||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | $ 2,212 | $ 2,098 | $ 7,553 | $ 6,976 | ||||||||||||||
| Operating Income (Loss) | 226 | 297 | 664 | 828 | ||||||||||||||
| Equity in earnings from investment in Enable | 81 | 68 | 208 | 199 | ||||||||||||||
| Assets | 22,228 | 22,228 | $ 22,736 | |||||||||||||||
| Total regulatory assets | 1,994 | 1,994 | 2,477 | |||||||||||||||
| Electric Transmission and Distribution [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | [1] | 897 | 843 | 2,502 | 2,234 | |||||||||||||
| Operating Income (Loss) | 227 | 254 | 523 | 511 | ||||||||||||||
| Electric Transmission and Distribution [Member] | Affiliates of NRG Energy, Inc. [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 213 | 221 | 543 | 540 | ||||||||||||||
| Electric Transmission and Distribution [Member] | Affiliates of Vistra Energy Corp. [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 79 | 72 | 192 | 172 | ||||||||||||||
| Natural Gas Distribution [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 402 | 390 | 2,032 | 1,767 | ||||||||||||||
| Operating Income (Loss) | 3 | 25 | 166 | 235 | ||||||||||||||
| Energy Services [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 910 | 861 | 3,008 | 2,964 | ||||||||||||||
| Operating Income (Loss) | (9) | 7 | (20) | 58 | ||||||||||||||
| Midstream Investments [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | [2] | 0 | 0 | 0 | 0 | |||||||||||||
| Operating Income (Loss) | [2] | 0 | 0 | 0 | 0 | |||||||||||||
| Equity in earnings from investment in Enable | 81 | 68 | 208 | 199 | ||||||||||||||
| Other Operations [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 3 | 4 | 11 | 11 | ||||||||||||||
| Operating Income (Loss) | 5 | 11 | (5) | 24 | ||||||||||||||
| Intersegment Eliminations [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | (18) | (18) | (83) | (58) | ||||||||||||||
| Assets | (681) | (681) | (654) | |||||||||||||||
| Intersegment Eliminations [Member] | Electric Transmission and Distribution [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 0 | 0 | 0 | 0 | ||||||||||||||
| Intersegment Eliminations [Member] | Natural Gas Distribution [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | (8) | (8) | (26) | (24) | ||||||||||||||
| Intersegment Eliminations [Member] | Energy Services [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | (10) | (10) | (57) | (34) | ||||||||||||||
| Intersegment Eliminations [Member] | Midstream Investments [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | [2] | 0 | 0 | 0 | 0 | |||||||||||||
| Intersegment Eliminations [Member] | Other Operations [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 0 | 0 | 0 | 0 | ||||||||||||||
| Operating Segments [Member] | Electric Transmission and Distribution [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Assets | 10,436 | 10,436 | 10,292 | |||||||||||||||
| Operating Segments [Member] | Natural Gas Distribution [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Assets | 6,557 | 6,557 | 6,608 | |||||||||||||||
| Operating Segments [Member] | Energy Services [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Assets | 1,253 | 1,253 | 1,521 | |||||||||||||||
| Operating Segments [Member] | Midstream Investments [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Assets | 2,457 | 2,457 | 2,472 | |||||||||||||||
| Operating Segments [Member] | Other Operations [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Assets | [3] | 2,206 | 2,206 | 2,497 | ||||||||||||||
| Pension and Other Postretirement Plans Costs [Member] | Other Operations [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Total regulatory assets | 566 | 566 | 600 | |||||||||||||||
| CERC Corp [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 1,312 | 1,251 | 5,040 | 4,731 | ||||||||||||||
| Operating Income (Loss) | (7) | 31 | 146 | 289 | ||||||||||||||
| Assets | 7,305 | 7,305 | 10,112 | |||||||||||||||
| Assets of discontinued operations | 0 | 0 | 2,472 | |||||||||||||||
| Total regulatory assets | 230 | 230 | 311 | |||||||||||||||
| CERC Corp [Member] | Natural Gas Distribution [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 402 | 390 | 2,032 | 1,767 | ||||||||||||||
| Operating Income (Loss) | 3 | 25 | 166 | 235 | ||||||||||||||
| CERC Corp [Member] | Energy Services [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 910 | 861 | 3,008 | 2,964 | ||||||||||||||
| Operating Income (Loss) | (9) | 7 | (20) | 58 | ||||||||||||||
| CERC Corp [Member] | Other Operations [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 0 | 0 | 0 | 0 | ||||||||||||||
| Operating Income (Loss) | (1) | (1) | 0 | (4) | ||||||||||||||
| CERC Corp [Member] | Intersegment Eliminations [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | (18) | (18) | (83) | (58) | ||||||||||||||
| Assets | (615) | (615) | (559) | |||||||||||||||
| CERC Corp [Member] | Intersegment Eliminations [Member] | Natural Gas Distribution [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | (8) | (8) | (26) | (24) | ||||||||||||||
| CERC Corp [Member] | Intersegment Eliminations [Member] | Energy Services [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | (10) | (10) | (57) | (34) | ||||||||||||||
| CERC Corp [Member] | Intersegment Eliminations [Member] | Other Operations [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Revenues | 0 | $ 0 | 0 | $ 0 | ||||||||||||||
| CERC Corp [Member] | Operating Segments [Member] | Natural Gas Distribution [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Assets | 6,557 | 6,557 | 6,608 | |||||||||||||||
| CERC Corp [Member] | Operating Segments [Member] | Energy Services [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Assets | 1,253 | 1,253 | 1,521 | |||||||||||||||
| CERC Corp [Member] | Operating Segments [Member] | Midstream Investments [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Assets | 0 | 0 | 0 | |||||||||||||||
| CERC Corp [Member] | Operating Segments [Member] | Other Operations [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Assets | 110 | 110 | 70 | |||||||||||||||
| Enable Midstream Partners [Member] | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff [Member] | CERC Corp [Member] | ||||||||||||||||||
| Segment Reporting Information [Line Items] | ||||||||||||||||||
| Assets of discontinued operations | $ 0 | [4] | $ 0 | [4] | $ 2,400 | $ 2,472 | [4] | |||||||||||
| ||||||||||||||||||
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- Definition Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount classified as assets attributable to disposal group held for sale or disposed of. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The net result for the period of deducting operating expenses from operating revenues. No definition available.
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| X | ||||||||||
- Definition The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||||
|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Interest, net of capitalized interest | $ 301 | $ 306 | ||||
| Income taxes, net | 89 | 14 | ||||
| Accounts payable related to capital expenditures | 140 | 111 | ||||
| Capital distribution associated with the Internal Spin | 0 | 0 | ||||
| Cash and cash equivalents | $ 293 | 293 | $ 260 | |||
| Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows | 331 | $ 233 | 331 | 233 | 296 | $ 381 |
| Prepaid expenses and other current assets [Member] | ||||||
| Restricted cash | 37 | 37 | 35 | |||
| Other [Member] | ||||||
| Restricted cash | 1 | 1 | 1 | |||
| Houston Electric [Member] | ||||||
| Interest, net of capitalized interest | 173 | 176 | ||||
| Income taxes, net | 122 | 76 | ||||
| Accounts payable related to capital expenditures | 87 | 70 | ||||
| Capital distribution associated with the Internal Spin | 0 | 0 | 0 | 0 | ||
| Cash and cash equivalents | 279 | 279 | 238 | |||
| Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows | 317 | 240 | 317 | 240 | 274 | 381 |
| Houston Electric [Member] | Prepaid expenses and other current assets [Member] | ||||||
| Restricted cash | 37 | 37 | 35 | |||
| Houston Electric [Member] | Other [Member] | ||||||
| Restricted cash | 1 | 1 | 1 | |||
| CERC Corp [Member] | ||||||
| Interest, net of capitalized interest | 85 | 86 | ||||
| Income taxes, net | 3 | 4 | ||||
| Accounts payable related to capital expenditures | 66 | 53 | ||||
| Capital distribution associated with the Internal Spin | 1,460 | 0 | 1,460 | 0 | ||
| Cash and cash equivalents | $ 1 | $ 1 | $ 1 | $ 1 | $ 12 | $ 1 |
| X | ||||||||||
- Definition Future cash outflow to pay for purchases of fixed assets that have occurred. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash paid, after deduction of cash paid for capitalized interest, for interest. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The value of the noncash (or part noncash) consideration given (for example, liability, equity) in a transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of a transaction not resulting in cash receipts or cash payments in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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| X | ||||||||||
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| X | ||||||||||
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| X | ||||||||||
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Related Party Transactions (Houston Electric and CERC) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
Dec. 31, 2017 |
||||||
| Related Party Transaction [Line Items] | ||||||||||
| Capital distribution to parent associated with the Internal Spin | $ 0 | $ 0 | ||||||||
| Houston Electric [Member] | ||||||||||
| Related Party Transaction [Line Items] | ||||||||||
| Interest income (expense) (1) | [1] | $ 1 | $ 1 | 1 | 3 | |||||
| Cash dividends paid to parent | 60 | 45 | 123 | 87 | ||||||
| Cash contribution from parent | 0 | 0 | 0 | 0 | ||||||
| Capital distribution to parent associated with the Internal Spin | 0 | 0 | 0 | 0 | ||||||
| Houston Electric [Member] | Operation and maintenance expense [Member] | ||||||||||
| Related Party Transaction [Line Items] | ||||||||||
| Net affiliate service charges (billings) | (3) | (1) | (8) | (6) | ||||||
| Houston Electric [Member] | CenterPoint Energy [Member] | Operation and maintenance expense [Member] | ||||||||||
| Related Party Transaction [Line Items] | ||||||||||
| Corporate service charges | 47 | 41 | 138 | 127 | ||||||
| CERC Corp [Member] | ||||||||||
| Related Party Transaction [Line Items] | ||||||||||
| Interest income (expense) (1) | [1] | (2) | 0 | (4) | 0 | |||||
| Cash dividends paid to parent | 75 | 89 | 286 | 337 | ||||||
| Cash contribution from parent | 600 | 0 | 600 | 38 | ||||||
| Capital distribution to parent associated with the Internal Spin | 1,460 | 0 | 1,460 | 0 | ||||||
| CERC Corp [Member] | Operation and maintenance expense [Member] | ||||||||||
| Related Party Transaction [Line Items] | ||||||||||
| Net affiliate service charges (billings) | 3 | 1 | 8 | 6 | ||||||
| CERC Corp [Member] | CenterPoint Energy [Member] | Operation and maintenance expense [Member] | ||||||||||
| Related Party Transaction [Line Items] | ||||||||||
| Corporate service charges | $ 36 | $ 30 | $ 105 | $ 93 | ||||||
| Investments [Member] | Houston Electric [Member] | ||||||||||
| Related Party Transaction [Line Items] | ||||||||||
| Weighted average interest rate | 2.45% | 2.45% | 1.90% | |||||||
| Investments [Member] | CERC Corp [Member] | ||||||||||
| Related Party Transaction [Line Items] | ||||||||||
| Weighted average interest rate | 2.45% | 2.45% | 1.90% | |||||||
| Accounts and notes receivable (payable) - affiliate companies [Member] | Houston Electric [Member] | ||||||||||
| Related Party Transaction [Line Items] | ||||||||||
| Money pool investments (borrowings) (1) | [2] | $ (75) | $ (75) | $ (60) | ||||||
| Accounts and notes receivable (payable) - affiliate companies [Member] | CERC Corp [Member] | ||||||||||
| Related Party Transaction [Line Items] | ||||||||||
| Money pool investments (borrowings) (1) | [2] | $ 0 | $ 0 | $ (570) | ||||||
| ||||||||||
| X | ||||||||||
- Definition Net interest income (expense) related to affiliate investments or borrowings No definition available.
|
| X | ||||||||||
- Definition Represents investments in or borrowings from the parent company's money pool. No definition available.
|
| X | ||||||||||
- Definition Weighted average interest rate of outstanding investments in money pool. No definition available.
|
| X | ||||||||||
- Definition Amount of net service charges from (billings to) related party during the period, excluding transactions that are eliminated in consolidated or combined financial statements. No definition available.
|
| X | ||||||||||
- Definition The value of the noncash (or part noncash) consideration given (for example, liability, equity) in a transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of a transaction not resulting in cash receipts or cash payments in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The cash inflow from parent as a source of financing that is recorded as additional paid in capital. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Amount of selling, general and administrative expenses resulting from transactions, excluding transactions that are eliminated in consolidated or combined financial statements, with related party. No definition available.
|
| X | ||||||||||
- Details
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Equity (CenterPoint Energy) (Details) |
3 Months Ended | 9 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Oct. 23, 2018
$ / shares
|
Oct. 01, 2018
USD ($)
day
$ / shares
shares
|
Aug. 22, 2018
USD ($)
day
$ / shares
shares
|
Dec. 13, 2017
$ / shares
|
Sep. 30, 2018
USD ($)
$ / shares
|
Sep. 30, 2017
$ / shares
|
Sep. 30, 2018
USD ($)
$ / shares
|
Sep. 30, 2017
USD ($)
$ / shares
|
Dec. 31, 2017
USD ($)
$ / shares
|
||||
| Class of Stock [Line Items] | ||||||||||||
| Dividends Declared Per Share | $ 0.2775 | $ 0.2775 | $ 0.2675 | $ 0.5550 | [1] | $ 0.8025 | ||||||
| Proceeds from issuance of Series A Preferred Stock, net | $ | $ 790,000,000 | $ 0 | ||||||||||
| Series A Preferred Stock [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Stock issued (in shares) | shares | 800,000 | |||||||||||
| Preferred stock par value (in dollars per share) | $ 1,000 | $ 0.01 | $ 0.01 | $ 0 | ||||||||
| Preferred stock liquidation preference | $ | $ 800,000,000 | $ 800,000 | $ 800,000 | $ 0 | ||||||||
| Preferred stock liquidation preference (per share) | $ 1,000 | |||||||||||
| Preferred stock dividend rate | 6.125% | |||||||||||
| Preferred stock redemption price (per share) | $ 1,000 | |||||||||||
| Preferred stock convertible threshold (in days) | day | 120 | |||||||||||
| Subsequent Event [Member] | Series B Preferred Stock [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Preferred stock liquidation preference | $ | $ 978,000,000 | |||||||||||
| Preferred stock liquidation preference (per share) | $ 1,000 | |||||||||||
| Preferred Stock, Convertible, Conversion Price | $ 1,000 | |||||||||||
| Preferred stock dividend rate | 7.00% | |||||||||||
| Proceeds from issuance of Series B Preferred Stock | $ | $ 950,000,000 | |||||||||||
| Conversion rate per share | 0.05 | |||||||||||
| Preferred Stock, Convertible, Threshold Consecutive Calendar Days | day | 20 | |||||||||||
| Subsequent Event [Member] | Depositary Share [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Stock issued (in shares) | shares | 19,550,000 | |||||||||||
| Number of depositary shares eligible for conversion (in shares) | shares | 20 | |||||||||||
| Preferred Stock, Convertible, Conversion Price | $ 50 | |||||||||||
| Subsequent Event [Member] | Common Stock [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Dividends Declared Per Share | $ 0.2775 | |||||||||||
| Stock issued (in shares) | shares | 69,633,027 | |||||||||||
| Common stock issued per share price | $ 27.25 | |||||||||||
| Proceeds from issuance of common stock | $ | $ 1,844,000,000 | |||||||||||
| Plus LIBOR Spread [Member] | Series A Preferred Stock [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Preferred stock dividend rate | 3.27% | |||||||||||
| Minimum [Member] | Subsequent Event [Member] | Series B Preferred Stock [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Convertible Preferred Stock, Shares Issued upon Conversion | shares | 30.5820 | |||||||||||
| Preferred Stock, Convertible, Stock Price Trigger | $ 27.2494 | |||||||||||
| Minimum [Member] | Subsequent Event [Member] | Series B Depositary Shares [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Preferred Stock, Convertible, Stock Price Trigger | $ 27.2494 | |||||||||||
| Minimum [Member] | Subsequent Event [Member] | Depositary Share [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Convertible Preferred Stock, Shares Issued upon Conversion | shares | 1.5291 | |||||||||||
| Maximum [Member] | Subsequent Event [Member] | Series B Preferred Stock [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Convertible Preferred Stock, Shares Issued upon Conversion | shares | 36.6980 | |||||||||||
| Preferred Stock, Convertible, Stock Price Trigger | $ 32.6990 | |||||||||||
| Maximum [Member] | Subsequent Event [Member] | Series B Depositary Shares [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Preferred Stock, Convertible, Stock Price Trigger | $ 32.6990 | |||||||||||
| Maximum [Member] | Subsequent Event [Member] | Depositary Share [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Convertible Preferred Stock, Shares Issued upon Conversion | shares | 1.8349 | |||||||||||
| Over-Allotment Option [Member] | Subsequent Event [Member] | Series B Depositary Shares [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Stock issued (in shares) | shares | 2,550,000 | |||||||||||
| Over-Allotment Option [Member] | Subsequent Event [Member] | Common Stock [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Stock issued (in shares) | shares | 9,082,568 | |||||||||||
| 120 Days After Conclusion of Review or Appeal [Member] | Series A Preferred Stock [Member] | ||||||||||||
| Class of Stock [Line Items] | ||||||||||||
| Preferred stock redemption price (per share) | $ 1,020 | |||||||||||
| Preferred stock redemption percentage of liquidation value | 102.00% | |||||||||||
| ||||||||||||
| X | ||||||||||
- Definition Represents the ratio of interest of one depositary share in a share of Series B Preferred Stock No definition available.
|
| X | ||||||||||
- Definition The price per share of the conversion feature embedded in the preferred stock. No definition available.
|
| X | ||||||||||
- Definition Price of the entity's common stock which would be required to be attained for the conversion feature embedded in the preferred stock to become effective. No definition available.
|
| X | ||||||||||
- Definition Threshold period of consecutive calendar days for fundamental change conversion. No definition available.
|
| X | ||||||||||
- Definition The percentage of the liquidation value per share of preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. No definition available.
|
| X | ||||||||||
- Definition Threshold period of specified days within which entity has option to redeem preferred stock. No definition available.
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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| X | ||||||||||
- Definition Aggregate dividends declared during the period for each share of common stock outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The number of shares converted in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Number of shares issued for each share of convertible preferred stock that is converted. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The percentage rate used to calculate dividend payments on preferred stock. No definition available.
|
| X | ||||||||||
- Definition The per share liquidation preference (or restrictions) of nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) that has a preference in involuntary liquidation considerably in excess of the par or stated value of the shares. The liquidation preference is the difference between the preference in liquidation and the par or stated values of the share. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Value of the difference between preference in liquidation and the par or stated values of the preferred shares. No definition available.
|
| X | ||||||||||
- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of this preferred stock are solely within the control of the issuer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition The cash inflow from the additional capital contribution to the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The cash inflow from issuance of preferred stocks identified as being convertible into another form of financial instrument, typically the entity's common stock. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
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- Definition Proceeds from issuance of capital stock which provides for a specific dividend that is paid to the shareholders before any dividends to common stockholders and which takes precedence over common stockholders in the event of liquidation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction. No definition available.
|
| X | ||||||||||
- Definition Per share or per unit amount of equity securities issued. No definition available.
|
| X | ||||||||||
- Definition Number of new stock issued during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
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Subsequent Events (CenterPoint Energy and CERC) (Details) $ / shares in Units, $ in Millions |
3 Months Ended | 9 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Nov. 06, 2018
USD ($)
$ / shares
|
Oct. 23, 2018
$ / shares
|
Oct. 01, 2018 |
Dec. 13, 2017
$ / shares
|
Sep. 30, 2018
$ / shares
|
Sep. 30, 2017
$ / shares
|
Sep. 30, 2018
$ / shares
|
[1] |
Sep. 30, 2017
$ / shares
|
Oct. 05, 2018
USD ($)
|
|||
| Subsequent Event [Line Items] | ||||||||||||
| Quarterly cash dividend/distribution declared per share | $ 0.2775 | $ 0.2775 | $ 0.2675 | $ 0.5550 | $ 0.8025 | |||||||
| Subsequent Event [Member] | ||||||||||||
| Subsequent Event [Line Items] | ||||||||||||
| Aggregate principal amount of debt issued | $ | $ 1,500 | |||||||||||
| Subsequent Event [Member] | Common Units [Member] | ||||||||||||
| Subsequent Event [Line Items] | ||||||||||||
| Dividends payable, date declared | Oct. 23, 2018 | |||||||||||
| Quarterly cash dividend/distribution declared per share | $ 0.2775 | |||||||||||
| Dividends payable, date to be paid | Dec. 13, 2018 | |||||||||||
| Dividends payable, date of record | Nov. 15, 2018 | |||||||||||
| Subsequent Event [Member] | Series B Preferred Stock [Member] | ||||||||||||
| Subsequent Event [Line Items] | ||||||||||||
| Dividends payable, date declared | Oct. 23, 2018 | |||||||||||
| Dividends payable, date to be paid | Dec. 01, 2018 | |||||||||||
| Dividends payable, date of record | Nov. 15, 2018 | |||||||||||
| Preferred stock dividends declared per share | $ 11.6667 | |||||||||||
| Depositary share interest in a share of Series B Preferred Stock | 0.05 | |||||||||||
| Subsequent Event [Member] | Series B Depositary Shares [Member] | ||||||||||||
| Subsequent Event [Line Items] | ||||||||||||
| Preferred stock dividends declared per share | $ 0.5833 | |||||||||||
| Subsequent Event [Member] | Enable Midstream Partners [Member] | Common Units [Member] | ||||||||||||
| Subsequent Event [Line Items] | ||||||||||||
| Expected cash distribution from equity method investment | $ | $ 74 | |||||||||||
| Subsequent Event [Member] | Enable Midstream Partners [Member] | Series A Preferred Units [Member] | ||||||||||||
| Subsequent Event [Line Items] | ||||||||||||
| Expected cash distribution from cost method investment | $ | $ 9 | |||||||||||
| Common Units [Member] | Subsequent Event [Member] | Enable Midstream Partners [Member] | ||||||||||||
| Subsequent Event [Line Items] | ||||||||||||
| Quarterly Cash Distribution, Declaration Date | Nov. 06, 2018 | |||||||||||
| Quarterly Cash Distribution, Distributions Declared, Per Unit | $ 0.318 | |||||||||||
| Series A Preferred Units [Member] | Subsequent Event [Member] | Enable Midstream Partners [Member] | ||||||||||||
| Subsequent Event [Line Items] | ||||||||||||
| Quarterly Cash Distribution, Declaration Date | Nov. 06, 2018 | |||||||||||
| Quarterly Cash Distribution, Distributions Declared, Per Unit | $ 0.625 | |||||||||||
| ||||||||||||
| X | ||||||||||
- Definition This item represents disclosure of the amount of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporation; these investments are accounted for under the cost method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities. No definition available.
|
| X | ||||||||||
- Definition Represents the ratio of interest of one depositary share in a share of Series B Preferred Stock No definition available.
|
| X | ||||||||||
- Definition Aggregate dividends declared during the period for each share of common stock outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Face (par) amount of debt instrument at time of issuance. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Date of declaration for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Per unit of ownership amount of cash distributions declared to unit-holder of a limited partnership (LP). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Date the declared dividend will be paid, in CCYY-MM-DD format. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Date the dividend to be paid was declared, in CCYY-MM-DD format. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format. No definition available.
|
| X | ||||||||||
- Definition Amount of distribution received from equity method investee for return on investment, classified as operating activities. Excludes distribution for return of investment, classified as investing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Aggregate dividends declared during the period for each share of preferred stock outstanding. No definition available.
|
| X | ||||||||||
- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. No definition available.
|
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