View Filing Data

Document and Entity Information Document - USD ($)	9 Months Ended
Document and Entity Information Document - USD ($)	Sep. 30, 2015	Oct. 23, 2015	Jun. 30, 2014
Entity Information [Line Items]
Entity Registrant Name	CENTERPOINT ENERGY HOUSTON ELECTRIC LLC
Entity Central Index Key	0000048732
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q/A
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3
Amendment Flag	true
Amendment Description	CenterPoint Energy Houston Electric, LLC (CenterPoint Houston or the Company) hereby amends Items 1 and 4 of Part I and Item 6 of Part II of its Quarterly Report on Form 10-Q for the period ended September 30, 2015 as originally filed on November 9, 2015 (Form 10-Q) to reflect the restatement of the Company’s unaudited condensed statement of consolidated cash flows as discussed in Note 10. For purposes of this Form 10-Q/A, and in accordance with Rule 12b-15 under the Securities Exchange Act of 1934, as amended, each item of the Form 10-Q that was affected by the restatement has been amended to the extent affected and restated in its entirety. No attempt has been made in this Form 10-Q/A to update other disclosures as presented in the Form 10-Q except as required to reflect the effects of the restatement. Accordingly, this Form 10-Q/A should be read in conjunction with the Company’s SEC filings made subsequent to the filing of the Form 10-Q, including any amendments of those filings. In addition, this Form 10-Q/A includes updated certifications from the Company’s CEO and CFO as Exhibits 31.1, 31.2, 32.1 and 32.2.
Entity Common Stock, Shares Outstanding		1,000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 0

CONDENSED STATEMENTS OF CONSOLIDATED INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues	$ 827	$ 839	$ 2,149	$ 2,167
Expenses:
Operation and maintenance	326	321	953	912
Depreciation and amortization	201	230	526	602
Taxes other than income taxes	56	56	167	170
Total	583	607	1,646	1,684
Operating Income	244	232	503	483
Other Income (Expense):
Interest and other finance charges	(30)	(27)	(88)	(80)
Interest on transition and system restoration bonds	(25)	(30)	(80)	(90)
Other, net	6	4	16	11
Total	(49)	(53)	(152)	(159)
Income Before Income Taxes	195	179	351	324
Income tax expense	71	60	127	113
Net Income	$ 124	$ 119	$ 224	$ 211

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Current Assets:
Cash and cash equivalents ($215 and $290 related to VIEs, respectively)	$ 217	$ 290
Accounts and notes receivable ($73 and $58 related to VIEs, respectively), less bad debt reserve of $1 and $3, respectively	302	237
Accounts and notes receivable–affiliated companies	9	119
Accrued unbilled revenues	112	96
Inventory	125	126
Taxes receivable	0	103
Deferred tax asset	2	2
Other ($38 and $47 related to VIEs, respectively)	46	74
Total current assets	813	1,047
Property, Plant and Equipment:
Property, plant and equipment	9,941	9,393
Less: accumulated depreciation and amortization	3,191	3,050
Property, plant and equipment, net	6,750	6,343
Regulatory assets ($2,465 and $2,738 related to VIEs, respectively)	2,355	2,629
Other	44	34
Total other assets	2,399	2,663
Total Assets	9,962	10,053
Current Liabilities:
Current portion of VIE transition and system restoration bonds long-term debt	390	372
Accounts payable	120	148
Accounts and notes payable–affiliated companies	215	121
Taxes accrued	128	104
Interest accrued	63	75
Other	94	109
Total current liabilities	1,010	929
Other Liabilities:
Deferred income taxes, net	1,899	2,001
Benefit obligations	260	260
Regulatory liabilities	567	537
Other	58	54
Total other liabilities	2,784	2,852
Long-term Debt:
VIE transition and system restoration bonds	2,346	2,674
Other	2,006	2,006
Total long-term debt	4,352	4,680
Commitments and Contingencies (Note 8)
Member’s Equity:
Common stock	0	0
Paid-in capital	1,322	1,322
Retained earnings	494	270
Total member’s equity	1,816	1,592
Total Liabilities and Member’s Equity	$ 9,962	$ 10,053

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) Balance Sheet Parenthetical - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Cash and Cash Equivalents	$ 217	$ 290
Allowance for Doubtful Accounts Receivable, Current	1	3
Accounts and notes receivable, net	302	237
Other	46	74
Assets, Noncurrent [Abstract]
Regulatory assets	2,355	2,629
Variable Interest Entity, Primary Beneficiary [Member]
Cash and Cash Equivalents	215	290
Accounts and notes receivable, net	73	58
Other	38	47
Assets, Noncurrent [Abstract]
Regulatory assets	$ 2,465	$ 2,738

CONDENSED STATEMENTS OF CONSOLIDATED CASH FLOWS (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash Flows from Operating Activities:
Net income	$ 224	$ 211
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	526	602
Amortization of deferred financing costs	11	12
Deferred income taxes	(114)	(95)
Changes in other assets and liabilities:
Accounts and notes receivable, net	(81)	(99)
Accounts receivable/payable–affiliated companies	(23)	(9)
Inventory	1	(9)
Accounts payable	(16)	0
Taxes receivable	103	0
Interest and taxes accrued	12	(60)
Net regulatory assets and liabilities	36	(7)
Other current assets	19	11
Other current liabilities	(15)	(18)
Other assets	(1)	0
Other liabilities	5	10
Other, net	0	(6)
Net cash provided by operating activities	687	543
Cash Flows from Investing Activities:
Capital expenditures	(677)	(588)
Decrease (increase) in notes receivable–affiliated companies	107	(43)
Decrease (increase) in restricted cash of transition and system restoration bond companies	9	(9)
Other, net	(9)	(7)
Net cash used in investing activities	(570)	(647)
Cash Flows from Financing Activities:
Proceeds from long-term debt	0	600
Payments of long-term debt	(310)	(477)
Increase (decrease) in short-term notes payable–affiliated companies	120	(3)
Debt issuance costs	0	(7)
Other, net	0	(1)
Net cash provided by (used in) financing activities	(190)	112
Net Increase (Decrease) in Cash and Cash Equivalents	(73)	8
Cash and Cash Equivalents at Beginning of Period	290	207
Cash and Cash Equivalents at End of Period	217	215
Cash Payments:
Interest, net of capitalized interest	169	186
Income taxes, net	157	221
Non-cash transactions:
Accounts payable related to capital expenditures	$ 52	$ 35

Background and Basis of Presentation	9 Months Ended
Background and Basis of Presentation	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Background and Basis of Presentation General. Included in this Quarterly Report on Form 10-Q (Form 10-Q) of CenterPoint Energy Houston Electric, LLC are the condensed consolidated interim financial statements and notes (Interim Condensed Financial Statements) of CenterPoint Energy Houston Electric, LLC and its subsidiaries (collectively, CenterPoint Houston). The Interim Condensed Financial Statements are unaudited, omit certain financial statement disclosures and should be read with the Annual Report on Form 10-K of CenterPoint Houston for the year ended December 31, 2014. Background. CenterPoint Houston engages in the electric transmission and distribution business in the Texas Gulf Coast area that includes the city of Houston. CenterPoint Houston is an indirect, wholly-owned subsidiary of CenterPoint Energy, Inc. (CenterPoint Energy), a public utility holding company. At September 30, 2015, CenterPoint Houston had the following subsidiaries: CenterPoint Energy Transition Bond Company, LLC, CenterPoint Energy Transition Bond Company II, LLC, CenterPoint Energy Transition Bond Company III, LLC, CenterPoint Energy Restoration Bond Company, LLC and CenterPoint Energy Transition Bond Company IV, LLC. The transition and system restoration bond companies, which are classified as variable interest entities (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 Houston have no recourse to any assets or revenues of the transition and system restoration bond companies. The bonds issued by these VIEs are payable only from and secured by transition and system restoration property, and the bondholders have no recourse to the general credit of CenterPoint Houston. 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. CenterPoint Houston’s 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 CenterPoint Houston’s 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, (b) timing of maintenance and other expenditures and (c) acquisitions and dispositions of businesses, assets and other interests.

New Accounting Pronouncements	9 Months Ended
New Accounting Pronouncements	Sep. 30, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	New Accounting Pronouncements In February 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis (ASU 2015-02). ASU 2015-02 changes the analysis that reporting organizations must perform to evaluate whether they should consolidate certain legal entities, such as limited partnerships. The changes include, among others, modification of the evaluation of whether limited partnerships and similar legal entities are variable interest entities (VIEs) or voting interest entities and elimination of the presumption that a general partner should consolidate a limited partnership. ASU 2015-02 does not amend the related party guidance for situations in which power is shared between two or more entities that hold interests in a VIE. ASU 2015-02 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2015. CenterPoint Houston will adopt ASU 2015-02 on January 1, 2016 and is currently assessing the impact, if any, that this standard will have on its financial position, results of operations, cash flows and disclosures. In April 2015, the FASB issued Accounting Standards Update No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Cost (ASU 2015-03). ASU 2015-03 requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by ASU 2015-03. CenterPoint Houston will adopt ASU 2015-03 retrospectively on January 1, 2016, which will result in a reduction of both other long-term assets and long-term debt on its Condensed Consolidated Balance Sheets. CenterPoint Houston had debt issuance costs of $23 million and $26 million included in other long-term assets on its Condensed Consolidated Balance Sheets as of September 30, 2015 and December 31, 2014, respectively. In April 2015, the FASB issued Accounting Standards Update No. 2015-05, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40) (ASU 2015-05). ASU 2015-05 provides guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The guidance will not change a customer’s accounting for service contracts. ASU 2015-05 is effective for fiscal years, and interim periods within the fiscal years, beginning after December 15, 2015 and may be adopted either prospectively or retrospectively. CenterPoint Houston will adopt ASU 2015-05 on January 1, 2016 and is currently assessing the impact that this standard will have on its financial position, results of operations, cash flows and disclosures. In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) (ASU 2014-09), which supersedes most current revenue recognition guidance. ASU 2014-09 provides a comprehensive new revenue recognition model that requires revenue to be recognized in a manner that depicts the transfer of goods or services to a customer at an amount that reflects the consideration expected to be received in exchange for those goods or services. ASU 2014-09 was initially effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is not permitted, and entities have the option of using either a full retrospective or a modified retrospective adoption approach. In August 2015, the FASB issued Accounting Standard Update No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date, which delays the effective date of ASU 2014-09 by one year. CenterPoint Houston is currently evaluating the impact that ASU 2014-09 will have on its financial position, results of operations, cash flows and disclosures, and may adopt ASU 2014-09 on January 1, 2018 as permitted by the new guidance. In July 2015, the FASB issued Accounting Standards Update No. 2015-11, Inventory (Topic 330) Simplifying the Measurement of Inventory (ASU 2015-11). ASU 2015-11 changes the subsequent measurement guidance for inventory accounted for using methods other than the last in, first out (LIFO) and Retail Inventory methods. Companies will subsequently measure inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. Subsequent measurement is unchanged for inventory measured using LIFO or the retail inventory method. ASU 2015-11 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, with early adoption permitted. CenterPoint Houston does not believe that ASU 2015-11 will have a material impact on its financial position, results of operations, cash flows and disclosures. Management believes that other recently issued standards, which are not yet effective, will not have a material impact on CenterPoint Houston’s consolidated financial position, results of operations or cash flows upon adoption.

Employee Benefit Plans

9 Months Ended

Sep. 30, 2015

Compensation and Retirement Disclosure [Abstract]

Pension and Other Postretirement Benefits Disclosure [Text Block]

Employee Benefit Plans

CenterPoint Houston’s employees participate in CenterPoint Energy’s postretirement benefit plan. CenterPoint Houston’s net periodic cost includes the following components relating to postretirement benefits:



	Three Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
	(in millions)
Service cost	$	—		$	—		$	1		$	—
Interest cost	4			4			10			11
Expected return on plan assets	(2		)	(2		)	(5		)	(5		)
Amortization of prior service credit	—			—			(1		)	(1		)
Amortization of loss	—			—			2			1
Amortization of transition obligation	—			1			—			3
Net periodic cost	$	2		$	3		$	7		$	9

CenterPoint Houston expects to contribute approximately $7 million to its postretirement benefit plan in 2015, of which $2 million and $6 million were contributed during the three and nine months ended September 30, 2015, respectively.

Regulatory Accounting	9 Months Ended
Regulatory Accounting	Sep. 30, 2015
regulatory accounting [Abstract]
Regulatory Matters [Text Block]	Regulatory Accounting As of September 30, 2015, CenterPoint Houston has not recognized an allowed equity return of $405 million because such return will be recognized as it is recovered in rates. During the three months ended September 30, 2015 and 2014, CenterPoint Houston recognized approximately $16 million and $20 million, respectively, of the allowed equity return not previously recognized. During the nine months ended September 30, 2015 and 2014, CenterPoint Houston recognized approximately $37 million and $52 million, respectively, of the allowed equity return not previously recognized.

Fair Value Measurements

9 Months Ended

Sep. 30, 2015

Fair Value Disclosures [Abstract]

Fair Value Disclosures [Text Block]

Fair Value Measurements

Assets and liabilities that are recorded at fair value in the 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 are investments listed in active markets. At September 30, 2015 and December 31, 2014, CenterPoint Houston held Level 1 investments of $34 million and $43 million, respectively, which were primarily investments in money market funds and are included in other current assets in the Condensed Consolidated Balance Sheets.

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. CenterPoint Houston had no Level 2 assets or liabilities at either September 30, 2015 or December 31, 2014.

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 CenterPoint Houston’s judgments about the assumptions market participants would use in determining fair value. CenterPoint Houston had no Level 3 assets or liabilities at either September 30, 2015 or December 31, 2014.

CenterPoint Houston determines the appropriate level for each financial asset and liability on a quarterly basis and recognizes transfers between levels at the end of the reporting period. For the nine months ended September 30, 2015, there were no transfers between levels.

Estimated Fair Value of Financial Instruments

The fair values of cash and cash equivalents and short-term borrowings are estimated to be approximately equivalent to carrying amounts and have been excluded from the table below. The fair value of each debt instrument is determined by multiplying the principal amount of each debt instrument by the market price. These assets and liabilities, which are not measured at fair value in the Condensed Consolidated Balance Sheets but for which the fair value is disclosed, would be classified as Level 1 in the fair value hierarchy.



	September 30, 2015				December 31, 2014
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Financial liabilities:	(in millions)
Long-term debt	$	4,742	$	5,059	$	5,052	$	5,441

- 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.

+ References + Details

Related Party Transactions and Major Customers

9 Months Ended

Sep. 30, 2015

Related Party Transactions and Major Customers

(a) Related Party Transactions

CenterPoint Houston participates in a “money pool” through which it 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. CenterPoint Houston had borrowings from the money pool of $120 million and investments in the money pool of $107 million at September 30, 2015 and December 31, 2014, respectively, which are included in accounts and notes payable-affiliated companies and accounts and notes receivable-affiliated companies, respectively, in the Condensed Consolidated Balance Sheets. Net interest income (expense) related to accounts and notes receivables and payables-affiliated companies was not material for either the three or nine months ended September 30, 2015 or 2014.

CenterPoint Energy provides some corporate services to CenterPoint Houston. The costs of services have been charged directly to CenterPoint Houston 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. These charges are not necessarily indicative of what would have been incurred had CenterPoint Houston not been an affiliate. Amounts charged to CenterPoint Houston for these services were as follows and are included primarily in operation and maintenance expenses:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
	(in millions)
Corporate service charges	$	40	$	41	$	126	$	117

(b) Major Customers

CenterPoint Houston’s transmission and distribution revenues from major customers are as follows:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
	(in millions)
Affiliates of NRG	$	222	$	222	$	578	$	552
Affiliates of Energy Future Holdings Corp.	$	67	$	59	$	170	$	140

- 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.

+ References + Details

Long-term Debt

9 Months Ended

Sep. 30, 2015

Long-term Debt, Unclassified [Abstract]

Debt Disclosure [Text Block]

Long-term Debt

Revolving Credit Facility. As of September 30, 2015 and December 31, 2014, CenterPoint Houston had the following revolving credit facility and utilization of such facility:



		September 30, 2015				December 31, 2014
Size of Facility		Loans		Letters of Credit		Loans		Letters of Credit
(in millions)
$	300	$	—	$	4	$	—	$	4

CenterPoint Houston’s $300 million credit facility, which is scheduled to terminate September 9, 2019, can be drawn at the London Interbank Offered Rate plus 1.125% based on CenterPoint Houston’s current credit ratings. The revolving credit facility contains a financial covenant which limits CenterPoint Houston’s consolidated debt (excluding transition and system restoration bonds) to an amount not to exceed 65% of its consolidated capitalization.

CenterPoint Houston was in compliance with all financial covenants as of September 30, 2015.

Other. As of both September 30, 2015 and December 31, 2014, CenterPoint Houston had issued $408 million of general mortgage bonds as collateral for long-term debt of CenterPoint Energy. These bonds are not reflected in the consolidated financial statements because of the contingent nature of the obligations. CenterPoint Energy held $290 million of its collateralized debt for future remarketing.

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies Legal Matters Gas Market Manipulation Cases. CenterPoint Energy, CenterPoint Houston or their predecessor, Reliant Energy, Incorporated (Reliant Energy), and certain of their former subsidiaries have been named as defendants in certain lawsuits described below. Under a master separation agreement between CenterPoint Energy and a former subsidiary, Reliant Resources, Inc. (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. In May 2009, RRI sold its Texas retail business to a subsidiary of NRG and RRI changed its name to RRI Energy, Inc. In December 2010, Mirant Corporation merged with and became a wholly-owned subsidiary of RRI, and RRI changed its name to GenOn Energy, Inc. (GenOn). In December 2012, NRG acquired GenOn through a merger in which GenOn became a wholly-owned subsidiary of NRG. None of the sale of the retail business, the merger with Mirant Corporation, or the acquisition of GenOn by NRG alters RRI’s (now GenOn’s) contractual obligations to indemnify CenterPoint Energy and its subsidiaries, including CenterPoint Houston, for certain liabilities, including their indemnification obligations regarding the gas market manipulation litigation. A large number of lawsuits were 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 have since been released or dismissed from all but one such case. CenterPoint Energy Services, Inc. (CES), a subsidiary of CenterPoint Energy Resources Corp., is a defendant in a case now pending in federal court in Nevada alleging a conspiracy to inflate Wisconsin natural gas prices in 2000–2002. In July 2011, the court issued an order dismissing the plaintiffs’ claims against other defendants in the case, each of whom had demonstrated Federal Energy Regulatory Commission jurisdictional sales for resale during the relevant period, based on federal preemption, and stayed the remainder of the case pending outcome of the appeals. The plaintiffs appealed this ruling to the U.S. Court of Appeals for the Ninth Circuit, which reversed the trial court’s dismissal of the plaintiffs’ claims. The U.S. Supreme Court agreed to review the case, and on April 21, 2015, affirmed the Ninth Circuit’s ruling and remanded the case to the district court for further proceedings. CenterPoint Energy and CES intend to continue vigorously defending against the plaintiffs’ claims on remand. CenterPoint Houston 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. Environmental Matters Asbestos. Some facilities owned by CenterPoint Energy contain or have contained asbestos insulation and other asbestos-containing materials. CenterPoint Energy or its subsidiaries, including CenterPoint Houston, have been named, along with numerous others, as a defendant in lawsuits filed by a number of individuals who claim injury due to exposure to asbestos. Some of the claimants have worked at locations owned by CenterPoint Energy or CenterPoint Houston, but most existing claims relate to facilities previously owned by CenterPoint Energy’s other subsidiaries or CenterPoint Houston. In 2004 and early 2005, CenterPoint Energy sold its generating business, to which most of these claims relate, to a company which is now an affiliate of NRG. Under the terms of the arrangements regarding separation of the generating business from CenterPoint Energy and its sale of that business, ultimate financial responsibility for uninsured losses from claims relating to the generating business has been assumed by the NRG affiliate, but CenterPoint Energy has agreed to continue to defend such claims to the extent they are covered by insurance maintained by CenterPoint Energy, subject to reimbursement of the costs of such defense by the NRG affiliate. CenterPoint Energy anticipates that additional claims like those received may be asserted in the future. Although their ultimate outcome cannot be predicted at this time, CenterPoint Houston or CenterPoint Energy, as appropriate, intends to continue vigorously contesting claims that it does not consider to have merit and, based on its experience to date, CenterPoint Houston does not expect these matters, either individually or in the aggregate, to have a material adverse effect on its financial condition, results of operations or cash flows. Other Environmental. From time to time, CenterPoint Houston identifies the presence of environmental contaminants on property where it conducts or has conducted operations. Other such sites involving contaminants may be identified in the future. CenterPoint Houston has and expects to continue to remediate identified sites consistent with its legal obligations. From time to time CenterPoint Houston has received notices from regulatory authorities or others regarding its status as a potentially responsible party in connection with sites found to require remediation due to the presence of environmental contaminants. In addition, CenterPoint Houston has been named from time to time as a defendant in litigation related to such sites. Although the ultimate outcome of such matters cannot be predicted at this time, CenterPoint Houston does not expect, based on its experience to date, these matters, either individually or in the aggregate, to have a material adverse effect on its financial condition, results of operations or cash flows. Other Proceedings CenterPoint Houston is 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, CenterPoint Houston is also a defendant 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. CenterPoint Houston regularly analyzes current information and, as necessary, provides accruals for probable liabilities on the eventual disposition of these matters. CenterPoint Houston does not expect the disposition of these matters to have a material adverse effect on its financial condition, results of operations or cash flows.

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes The effective tax rate reported for the three months ended September 30, 2015 was 36% compared to 34% for the same period in 2014. For the three months ended September 30, 2014, CenterPoint Houston recognized a tax benefit of $5 million based on the reversal of previously accrued taxes as a result of CenterPoint Energy’s filing of its 2013 consolidated federal income tax return. The effective tax rate reported for the nine months ended September 30, 2015 was 36% compared to 35% for the same period in 2014. CenterPoint Houston reported no uncertain tax liability as of September 30, 2015 and expects no significant change to the uncertain tax liability over the twelve-month period ending September 30, 2016. Tax years through 2013 have been audited and settled with the Internal Revenue Service (IRS). For 2014 and 2015, CenterPoint Energy is a participant in the IRS’s Compliance Assurance Process.

Restatement (Notes)

9 Months Ended

Sep. 30, 2015

Accounting Changes and Error Corrections [Abstract]

Accounting Changes and Error Corrections [Text Block]

Restatement of Condensed Statement of Consolidated Cash Flows

As disclosed in Note 6, CenterPoint Houston participates in a centralized cash management arrangement or money pool with affiliates. Investments in the money pool are included in the condensed consolidated balance sheets as accounts and notes receivable–affiliated companies, while borrowings are included in accounts and notes payable–affiliated companies. Under generally accepted accounting principles, receivables from an affiliate in a centralized cash management arrangement such as the money pool are considered loans, and corresponding changes should be classified in cash flows from investing activities in the statements of consolidated cash flows, while payables are considered borrowings and should be classified in cash flows from financing activities. Subsequent to the issuance of CenterPoint Houston’s consolidated financial statements for the three and nine months ended September 30, 2015, CenterPoint Houston determined that borrowings from the money pool were incorrectly classified in its condensed statement of consolidated cash flows, resulting in an overstatement of accounts receivable/payable–affiliated companies and net cash provided by operating activities by approximately $120 million, an understatement of increase in notes payable–affiliated companies by approximately $120 million and an overstatement of net cash used in financing activities by approximately $120 million. As a result, the accompanying condensed statement of consolidated cash flows for the nine months ended September 30, 2015 has been restated from the amounts previously reported to reflect correct cash flow classification of borrowings from the money pool. There was no effect on CenterPoint Houston’s previously reported statements of consolidated income, consolidated balance sheets, and statements of consolidated member’s equity for the three and nine months ended September 30, 2015.

A summary of the significant effects of the restatement is as follows:



	Nine Months Ended September 30, 2015
	As Restated			As Previously Reported
	(in millions)
Condensed Statements of Consolidated Cash Flows:
Cash Flows from Operating Activities:
Accounts receivable/payable–affiliated companies	$	(23	)	$	97
Net cash provided by operating activities	687			807
Cash Flows from Financing Activities:
Increase in notes payable–affiliated companies	120			—
Net cash used in financing activities	(190		)	(310		)

Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2015

Defined Benefit Plan Disclosure [Line Items]

Schedule of Defined Benefit Plans Disclosures [Table Text Block]



	Three Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
	(in millions)
Service cost	$	—		$	—		$	1		$	—
Interest cost	4			4			10			11
Expected return on plan assets	(2		)	(2		)	(5		)	(5		)
Amortization of prior service credit	—			—			(1		)	(1		)
Amortization of loss	—			—			2			1
Amortization of transition obligation	—			1			—			3
Net periodic cost	$	2		$	3		$	7		$	9

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2015

Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]

Fair Value, by Balance Sheet Grouping [Table Text Block]

Estimated Fair Value of Financial Instruments



	September 30, 2015				December 31, 2014
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Financial liabilities:	(in millions)
Long-term debt	$	4,742	$	5,059	$	5,052	$	5,441

Related Party Transactions and Major Customers (Tables)

9 Months Ended

Sep. 30, 2015



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
	(in millions)
Corporate service charges	$	40	$	41	$	126	$	117

Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]

CenterPoint Houston’s transmission and distribution revenues from major customers are as follows:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
	(in millions)
Affiliates of NRG	$	222	$	222	$	578	$	552
Affiliates of Energy Future Holdings Corp.	$	67	$	59	$	170	$	140

Long-term Debt (Tables)

9 Months Ended

Sep. 30, 2015

Line of Credit Facility [Line Items]

Schedule of Line of Credit Facilities [Table Text Block]

Revolving Credit Facility. As of September 30, 2015 and December 31, 2014, CenterPoint Houston had the following revolving credit facility and utilization of such facility:



		September 30, 2015				December 31, 2014
Size of Facility		Loans		Letters of Credit		Loans		Letters of Credit
(in millions)
$	300	$	—	$	4	$	—	$	4

Restatement (Tables)

9 Months Ended

Sep. 30, 2015

Error Corrections and Prior Period Adjustments Restatement [Line Items]

Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]

A summary of the significant effects of the restatement is as follows:



	Nine Months Ended September 30, 2015
	As Restated			As Previously Reported
	(in millions)
Condensed Statements of Consolidated Cash Flows:
Cash Flows from Operating Activities:
Accounts receivable/payable–affiliated companies	$	(23	)	$	97
Net cash provided by operating activities	687			807
Cash Flows from Financing Activities:
Increase in notes payable–affiliated companies	120			—
Net cash used in financing activities	(190		)	(310		)

New Accounting Pronouncements (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Other Noncurrent Assets [Member]
Unamortized Debt Issuance Expense	$ 23	$ 26

Employee Benefit Plans (Details) - Other Postretirement Benefit Plans, Defined Benefit [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 1	$ 0
Interest cost	4	4	10	11
Expected return on plan assets	(2)	(2)	(5)	(5)
Amortization of prior service credit	0	0	(1)	(1)
Amortization of loss	0	0	2	1
Amortization of transition obligation	0	1	0	3
Net periodic cost	2	$ 3	7	$ 9
Expected contribution to postretirement benefit plan in current year			7
Total contribution to the plan during the period	$ 2		$ 6

Regulatory Accounting (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Regulatory Accounting (Details) - USD ($) $ in Millions	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Unrecognized Amount Of Allowed Equity Return	$ 405		$ 405
Amount Of Allowed Equity Return Recognized In Period	$ 16	$ 20	$ 37	$ 52

Fair Value Measurements (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, including money market funds	$ 34	$ 43
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, including money market funds	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, including money market funds	0	0
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Long-term debt	4,742	5,052
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Long-term debt	$ 5,059	$ 5,441

Related Party Transactions and Major Customers (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Related Party Transaction [Line Items]
Money Pool Borrowings	$ (120)		$ (120)
Investments in Money Pool					$ 107
Corporate service charges	40	$ 41	126	$ 117
Sales to major customers	827	839	2,149	2,167
Affiliates of NRG Energy, Inc. [Member]
Related Party Transaction [Line Items]
Sales to major customers	222	222	578	552
Affiliates of Energy Future Holdings Corp. [Member]
Related Party Transaction [Line Items]
Sales to major customers	$ 67	$ 59	$ 170	$ 140

Long-term Debt (Details) - USD ($) $ in Millions	9 Months Ended
Long-term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 300	$ 300
General mortgage bonds used as collateral	408	408
CenterPoint Energy [Member]
Debt Instrument [Line Items]
Collateralized Debt Held For Future Remarketing	290	290
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Loans Outstanding	0	0
Letter of Credit [Member]
Debt Instrument [Line Items]
Loans Outstanding	$ 4	$ 4
Line of Credit [Member]
Debt Instrument [Line Items]
Percentage on limitation of debt to total capitalization under covenant	65.00%
Line of Credit [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate Description	1.125%

Commitments and Contingencies (Details)	Sep. 30, 2015
Gas Market Manipulation Cases [Member]
Loss Contingencies [Line Items]
Loss Contingency Pending Gas Market Manipulation Lawsuits Number	1

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Effective tax rate	36.00%	34.00%	36.00%	35.00%
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	$ (5)

Restatement (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Restatement (Details) - USD ($) $ in Millions	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts Receivable Payable, Affiliated Companies, Overstated Amount		$ 120
Net Cash Provided By Operating Activities, Overstated Amount	$ 120
Increase In Notes Payable, Affiliated Companies, Understated Amount		120
Net Cash Used in Financing Activites, Overstated Amount		120
Accounts receivable/payable–affiliated companies		(23)	$ (9)
Net cash provided by operating activities		687
Increase in notes payable–affiliated companies		120	$ (3)
Net cash used in financing activities		(190)
Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accounts receivable/payable–affiliated companies		97
Net cash provided by operating activities		807
Increase in notes payable–affiliated companies		0
Net cash used in financing activities		$ (310)