View Filing Data

Document and Entity Information Document - USD ($)	3 Months Ended
Document and Entity Information Document - USD ($)	Mar. 31, 2013	Apr. 18, 2013	Jun. 30, 2012
Entity Information [Line Items]
Entity Registrant Name	CENTERPOINT ENERGY INC.
Entity Central Index Key	0001130310
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		428,530,395
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 8,760,880,387

Condensed Statements of Consolidated Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues	$ 2,388	$ 2,084
Expenses:
Natural gas	1,224	969
Operation and maintenance	484	455
Depreciation and amortization	240	224
Taxes other than income taxes	108	98
Total	2,056	1,746
Operating Income	332	338
Other Income (Expense):
Gain on marketable securities	74	46
Loss on indexed debt securities	(51)	(33)
Interest and other finance charges	(98)	(110)
Interest on transition and system restoration bonds	(35)	(37)
Equity in earnings of unconsolidated affiliates	5	9
Other, net	6	6
Total	(99)	(119)
Income Before Income Taxes	233	219
Income tax expense	86	72
Net Income	$ 147	$ 147
Basic Earnings Per Share:
Basic Earnings Per Share	$ 0.34	$ 0.34
Diluted earnings per share:
Diluted Earnings Per Share	0.34	0.34
Dividends Declared Per Share	$ 0.2075	$ 0.2025
Weighted Average Shares Outstanding, Basic	427,961,000	426,499,000
Weighted Average Shares Outstanding, Diluted	429,672,000	428,492,000

Statement of Comprehensive Income Parentheticals (Parentheticals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Tax effects on adjustment to pension and other postretirement plans	$ 2	$ 2

Condensed Statements of Consolidated Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net income	$ 147	$ 147
Other comprehensive income:
Adjustment related to pension and other postretirement plans (net of tax of $2 and $2)	3	2
Total	3	2
Comprehensive income	$ 150	$ 149

- Definition

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References + Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Net of tax amount of other comprehensive income (loss) attributable to the parent entity.

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+ Details

Balance Sheet Parentheticals (Parentheticals) - USD ($) $ in Millions	Mar. 31, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 245	$ 646
Accounts receivable, net,	860	768
Prepaid expenses and other current assets	137	216
Other Assets:
Regulatory assets	$ 4,229	$ 4,324
Total common stock outstanding (in shares)	428,523,140	427,599,564
Variable Interest Entity, Primary Beneficiary [Member]
Current Assets:
Cash and cash equivalents	$ 166	$ 266
Accounts receivable, net,	65	68
Prepaid expenses and other current assets	53	54
Other Assets:
Regulatory assets	$ 3,470	$ 3,545

- 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.

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+ Details

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Mar. 31, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents ($266 and $166 related to VIEs at December 31, 2012 and March 31, 2013, respectively)	$ 245	$ 646
Investment in marketable securities	614	540
Accounts receivable, net ($68 and $65 related to VIEs at December 31, 2012 and March 31, 2013, respectively)	860	768
Accrued unbilled revenues	276	339
Natural gas inventory	22	145
Materials and supplies	181	177
Non-trading derivative assets	18	36
Taxes receivable	10	7
Prepaid expenses and other current assets ($54 and $53 related to VIEs at December 31, 2012 and March 31, 2013, respectively)	137	216
Total current assets	2,363	2,874
Property, Plant and Equipment:
Property, plant and equipment	18,598	18,377
Less accumulated depreciation and amortization	4,890	4,780
Property, plant and equipment, net	13,708	13,597
Other Assets:
Goodwill	1,468	1,468
Regulatory assets ($3,545 and $3,470 related to VIEs at December 31, 2012 and March 31, 2013, respectively)	4,229	4,324
Non-trading derivative assets	5	6
Investment in unconsolidated affiliates	400	405
Other	197	197
Total other assets	6,299	6,400
Total Assets	22,370	22,871
Current Liabilities:
Short-term borrowings	0	38
Current portion of VIE transition and system restoration bonds long-term debt	417	447
Current portion of indexed debt	139	138
Current portion of other long-term debt	524	815
Indexed debt securities derivative	319	268
Accounts payable	510	561
Taxes accrued	123	160
Interest accrued	128	150
Non-trading derivative liabilities	10	14
Accumulated deferred income taxes, net	609	604
Other	347	380
Total current liabilities	3,126	3,575
Other Liabilities:
Accumulated deferred income taxes, net	4,211	4,153
Non-trading derivative liabilities	2	2
Benefit obligations	1,137	1,143
Regulatory liabilities	1,135	1,093
Other	258	247
Total other liabilities	6,743	6,638
Long-term Debt:
VIE transition and system restoration bonds	3,269	3,400
Other	4,861	4,957
Total long-term debt	8,130	8,357
Commitments and Contingencies (Note 12)
Shareholders' Equity:
Common stock (427,599,564 shares and 428,523,140 shares outstanding at December 31, 2012 and March 31, 2013, respectively)	4	4
Additional paid-in capital	4,139	4,130
Retained earnings	360	302
Accumulated other comprehensive loss	(132)	(135)
Total shareholders' equity	4,371	4,301
Total Liabilities and Shareholders' Equity	$ 22,370	$ 22,871

Condensed Statements of Consolidated Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash Flows from Operating Activities:
Net income	$ 147	$ 147
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	240	224
Amortization of deferred financing costs	8	8
Deferred income taxes	57	64
Unrealized gain on marketable securities	(74)	(46)
Unrealized loss on indexed debt securities	51	33
Write-down of natural gas inventory	0	4
Equity in earnings of unconsolidated affiliates, net of distributions	4	2
Changes in other assets and liabilities:
Accounts receivable and unbilled revenues, net	(66)	193
Inventory	119	94
Taxes receivable	(3)	0
Accounts payable	(33)	(172)
Fuel cost recovery	105	(43)
Non-trading derivatives, net	7	(3)
Margin deposits, net	12	14
Interest and taxes accrued	(76)	(87)
Net regulatory assets and liabilities	39	42
Other current assets	8	(7)
Other current liabilities	(32)	(57)
Other assets	1	2
Other liabilities	7	8
Other, net	12	4
Net cash provided by operating activities	533	424
Cash Flows from Investing Activities:
Capital expenditures	(271)	(264)
Decrease (increase) in restricted cash of transition and system restoration bonds companies	1	(15)
Investment in unconsolidated affiliates	0	(4)
Other, net	(4)	(9)
Net cash used in investing activities	(274)	(292)
Cash Flows from Financing Activities:
Decrease in short-term borrowings, net	(38)	(53)
Proceeds from (payments of) commercial paper, net	61	(285)
Proceeds from long-term debt	0	1,695
Payments of long-term debt	(612)	(526)
Debt issuance costs	0	(8)
Payment of common stock dividends	(89)	(87)
Proceeds from issuance of common stock, net	1	2
Other, net	17	6
Net cash provided by (used in) financing activities	(660)	744
Net Increase (Decrease) in Cash and Cash Equivalents	(401)	876
Cash and Cash Equivalents at Beginning of Period	646	220
Cash and Cash Equivalents at End of Period	245	1,096
Cash Payments:
Interest, net of capitalized interest	147	178
Income taxes refunds, net	(3)	(8)
Non-cash transactions:
Accounts payable related to capital expenditures	$ 92	$ 88

Background and Basis of Presentation

3 Months Ended

Mar. 31, 2013

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Background and Basis of Presentation

General. Included in this Quarterly Report on Form 10-Q (Form 10-Q) of CenterPoint Energy, Inc. are the condensed consolidated interim financial statements and notes (Interim Condensed Financial Statements) of CenterPoint Energy, Inc. and its subsidiaries (collectively, CenterPoint Energy). 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 Energy for the year ended December 31, 2012 (CenterPoint Energy Form 10-K).

Background. CenterPoint Energy, Inc. is a public utility holding company. CenterPoint Energy’s operating subsidiaries own and operate electric transmission and distribution facilities, natural gas distribution facilities, interstate pipelines and natural gas gathering, processing and treating facilities. As of March 31, 2013, CenterPoint Energy’s indirect wholly owned subsidiaries included:


•	CenterPoint Energy Houston Electric, LLC (CenterPoint Houston), which engages in the electric transmission and distribution business in the Texas Gulf Coast area that includes the city of Houston; and

•

CenterPoint Energy Resources Corp. (CERC Corp. and, together with its subsidiaries, CERC), which owns and operates natural gas distribution systems (Gas Operations). Subsidiaries of CERC Corp. own interstate natural gas pipelines and gas gathering systems and provide various ancillary services. A wholly owned subsidiary of CERC Corp. offers variable and fixed-price physical natural gas supplies primarily to commercial and industrial customers and electric and gas utilities.

As of March 31, 2013, CenterPoint Energy had five variable interest entities (VIEs) consisting of transition and system restoration bond companies which it consolidates. The consolidated VIEs are wholly owned bankruptcy remote special purpose entities that were formed specifically for the purpose of securitizing transition and system restoration property. Creditors of CenterPoint Energy 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 Energy.

Basis of Presentation. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America 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 Energy’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 Energy’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 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.

For a description of CenterPoint Energy’s reportable business segments, see Note 14.

- Definition

The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure.

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+ Details

New Accounting Pronouncements	3 Months Ended
New Accounting Pronouncements	Mar. 31, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	New Accounting Pronouncements In February 2013, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update No. 2013-02, “Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income” (ASU 2013-02). The objective of ASU 2013-02 is to improve the transparency of changes in other comprehensive income and items reclassified out of Accumulated Other Comprehensive Income in financial statements. This new guidance is effective for a reporting entity's first reporting period beginning after December 15, 2012 and should be applied prospectively. CenterPoint Energy's adoption of this new guidance did not have a material impact on its financial position, results of operations or cash flows. In December 2011 and January 2013, the FASB issued Accounting Standards Update No. 2011-11, “Disclosures About Offsetting Assets and Liabilities” (ASU 2011-11) and No. 2013-01, “Clarifying the Scope of Disclosures About Offsetting Assets and Liabilities” (ASU 2013-01), respectively. The objective of ASU 2011-11 is to enhance disclosures about the nature of an entity's rights of setoff and related arrangements associated with its financial instruments and derivative instruments. The objective of ASU 2013-01 is to clarify which instruments and transactions are subject to ASU 2011-11. Both ASU 2011-11 and ASU 2013-01 are effective for a reporting entity's first reporting period beginning on or after January 1, 2013 and should be applied retrospectively. CenterPoint Energy's adoption of this new guidance did not have a material impact on its financial position, results of operations or cash flows. Management believes that other recently issued standards, which are not yet effective, will not have a material impact on CenterPoint Energy’s consolidated financial position, results of operations or cash flows upon adoption.

Employee Benefit Plans

3 Months Ended

Mar. 31, 2013

Compensation and Retirement Disclosure [Abstract]

Employee Benefit Plans

CenterPoint Energy’s net periodic cost includes the following components relating to pension and postretirement benefits:



	Three Months Ended March 31,
	2012						2013
	Pension Benefits(1)			Postretirement Benefits			Pension Benefits(1)			Postretirement Benefits
	(in millions)
Service cost	$	9		$	—		$	11		$	—
Interest cost	25			6			23			5
Expected return on plan assets	(30		)	(2		)	(34		)	(2		)
Amortization of prior service credit	2			1			2			—
Amortization of net loss	15			1			16			2
Amortization of transition obligation	—			2			—			2
Net periodic cost	$	21		$	8		$	18		$	7

________________


(1)	Net periodic cost in these tables is before considering amounts subject to overhead allocations for capital expenditure projects or for amounts subject to deferral for regulatory purposes.

CenterPoint Energy's changes in accumulated comprehensive loss related to defined benefit and postretirement plans are as follows:



	Three Months Ended March 31, 2013
	Pension and Postretirement Plans
	(in millions)

Beginning Balance	$	(132	)
Amounts reclassified from accumulated other comprehensive income:
Prior service cost (1)	1
Actuarial gains (1)	4
Total reclassifications from accumulated other comprehensive income	5
Tax expense	(2		)
Net current period other comprehensive income	3
Ending Balance	$	(129	)

________________


(1)	These accumulated other comprehensive components are included in the computation of net periodic cost.

CenterPoint Energy expects to contribute a total of approximately $92 million to its pension plans in 2013, of which approximately $8 million was contributed during the three months ended March 31, 2013. A contribution of approximately $27 million was made in April 2013.

CenterPoint Energy expects to contribute a total of approximately $17 million to its postretirement benefits plan in 2013, of which approximately $4 million was contributed during the three months ended March 31, 2013.

- Definition

The entire disclosure for pension and other postretirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-Paragraph 264
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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-Paragraph 5
-Subparagraph q
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 11: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 13: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Regulatory Accounting	3 Months Ended
Regulatory Accounting	Mar. 31, 2013
Regulatory Assets and Liabilities, Other Disclosures [Abstract]
Regulatory Matters	Regulatory Accounting As of March 31, 2013, CenterPoint Energy has not recognized an allowed equity return of $545 million because such return will be recognized as it is recovered in rates. During both the three months ended March 31, 2012 and 2013, CenterPoint Houston recognized approximately $8 million of the allowed equity return not previously recognized.

Derivative Instruments

3 Months Ended

Mar. 31, 2013

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Instruments

CenterPoint Energy is exposed to various market risks. These risks arise from transactions entered into in the normal course of business. CenterPoint Energy utilizes derivative instruments such as physical forward contracts, swaps and options to mitigate the impact of changes in commodity prices and weather on its operating results and cash flows. Such derivatives are recognized in CenterPoint Energy’s Condensed Consolidated Balance Sheets at their fair value unless CenterPoint Energy elects the normal purchase and sales exemption for qualified physical transactions. A derivative may be designated as a normal purchase or 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 all commodity price, weather and credit risk activities, including CenterPoint Energy’s marketing, risk management services and hedging activities. The committee’s duties are to establish CenterPoint Energy’s commodity risk policies, allocate board-approved commercial risk limits, approve the use of new products and commodities, monitor positions and ensure compliance with CenterPoint Energy’s risk management policies and procedures and limits established by CenterPoint Energy’s board of directors.

CenterPoint Energy’s 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.


(a)	Non-Trading Activities

Derivative Instruments. CenterPoint Energy enters into certain derivative instruments to manage physical commodity price risks and does not engage in proprietary or speculative commodity trading. These financial instruments do not qualify or are not designated as cash flow or fair value hedges.

Weather Hedges. CenterPoint Energy has weather normalization or other rate mechanisms that mitigate the impact of weather on its gas operations in Arkansas, Louisiana, Mississippi and Oklahoma. Gas Operations in Texas and Minnesota do not have such mechanisms. As a result, fluctuations from normal weather may have a significant positive or negative effect on Gas Operations’ results in these jurisdictions. CenterPoint Energy enters into heating-degree day swaps for these Gas Operations jurisdictions to mitigate the effect of fluctuations from normal weather on its results of operations and cash flows for the winter heating season. The swaps are based on ten-year normal weather. During the three months ended March 31, 2012 and 2013, CenterPoint Energy recognized gains of $6 million and losses of $3 million, respectively, related to these swaps. Weather hedge gains and losses are included in revenues in the Condensed Statements of Consolidated Income.


(b)	Derivative Fair Values and Income Statement Impacts

The following tables present information about CenterPoint Energy’s derivative instruments and hedging activities. The first four tables provide a balance sheet overview of CenterPoint Energy’s Derivative Assets and Liabilities as of December 31, 2012 and March 31, 2013, while the last table provides a breakdown of the related income statement impacts for the three months ended March 31, 2012 and 2013.



Fair Value of Derivative Instruments
		December 31, 2012
Total derivatives not designated as hedging instruments	Balance Sheet Location	Derivative Assets Fair Value		Derivative Liabilities Fair Value
		(in millions)
Natural gas derivatives (1) (2)	Current Assets: Non-trading derivative assets	$	37	$	1
Natural gas derivatives (1) (2)	Other Assets: Non-trading derivative assets	6		—
Natural gas derivatives (1) (2)	Current Liabilities: Non-trading derivative liabilities	5		27
Natural gas derivatives (1) (2)	Other Liabilities: Non-trading derivative liabilities	1		4
Indexed debt securities derivative	Current Liabilities	—		268
Total		$	49	$	300

________________


(1)	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 489 billion cubic feet (Bcf) or a net 101 Bcf long position. Of the net long position, basis swaps constitute 73 Bcf.

(2)

Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was a $26 million asset as shown on CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $9 million:



Offsetting of Natural Gas Derivative Assets and Liabilities
	December 31, 2012
	Gross Amounts Recognized (1)			Gross Amounts Offset in the Consolidated Balance Sheets			Net Amount Presented in the Consolidated Balance Sheets (2)
	(in millions)
Current Assets: Non-trading derivative assets	$	42		$	(6	)	$	36
Other Assets: Non-trading derivative assets	7			(1		)	6
Current Liabilities: Non-trading derivative liabilities	(28		)	14			(14		)
Other Liabilities: Non-trading derivative liabilities	(4		)	2			(2		)
Total	$	17		$	9		$	26

________________


(1)	Gross Amounts Recognized contain some derivative assets and liabilities that are not subject to master netting arrangements.


(2)	The derivative assets and liabilities on the Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default.



Fair Value of Derivative Instruments
		March 31, 2013
Total derivatives not designated as hedging instruments	Balance Sheet Location	Derivative Assets Fair Value		Derivative Liabilities Fair Value
		(in millions)
Natural gas derivatives (1) (2)	Current Assets: Non-trading derivative assets	$	26	$	8
Natural gas derivatives (1) (2)	Other Assets: Non-trading derivative assets	5		1
Natural gas derivatives (1) (2)	Current Liabilities: Non-trading derivative liabilities	1		11
Natural gas derivatives (1) (2)	Other Liabilities: Non-trading derivative liabilities	1		2
Indexed debt securities derivative	Current Liabilities	—		319
Total		$	33	$	341

________________


(1)	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 492 Bcf or a net 107 Bcf long position. Of the net long position, basis swaps constitute 57 Bcf.

(2)

Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was an $11 million asset as shown on CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of less than $1 million:



Offsetting of Natural Gas Derivative Assets and Liabilities
	March 31, 2013
	Gross Amounts Recognized (1)			Gross Amounts Offset in the Consolidated Balance Sheets			Net Amount Presented in the Consolidated Balance Sheets (2)
	(in millions)
Current Assets: Non-trading derivative assets	$	27		$	(9	)	$	18
Other Assets: Non-trading derivative assets	6			(1		)	5
Current Liabilities: Non-trading derivative liabilities	(19		)	9			(10		)
Other Liabilities: Non-trading derivative liabilities	(3		)	1			(2		)
Total	$	11		$	—		$	11

________________


(1)	Gross Amounts Recognized contain some derivative assets and liabilities that are not subject to master netting arrangements.


(2)	The derivative assets and liabilities on the Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default.

For CenterPoint Energy’s price stabilization activities of the Natural Gas Distribution business segment, the settled costs of derivatives are ultimately recovered through purchased gas adjustments. Accordingly, the net unrealized gains and losses associated with these contracts are recorded as net regulatory assets. Realized and unrealized gains and losses on other derivatives are recognized in the Condensed Statements of Consolidated Income as revenue for physical natural gas sales derivative contracts and as natural gas expense for financial natural gas derivatives and other physical natural gas derivatives. Unrealized gains and losses on indexed debt securities are recorded as Other Income (Expense) in the Condensed Statements of Consolidated Income.



Income Statement Impact of Derivative Activity
		Three Months Ended March 31,
Total derivatives not designated as hedging instruments	Income Statement Location	2012			2013
		(in millions)
Natural gas derivatives	Gains (Losses) in Revenue	$	51		$	(14	)
Natural gas derivatives (1)	Gains (Losses) in Expense: Natural Gas	(81		)	16
Indexed debt securities derivative	Gains (Losses) in Other Income (Expense)	(33		)	(51		)
Total		$	(63	)	$	(49	)

________________


(1)	The Gains (Losses) in Expense: Natural Gas includes $(38) million and $-0- of costs in 2012 and 2013, respectively, associated with price stabilization activities of the Natural Gas Distribution business segment that will be ultimately recovered through purchased gas adjustments.


(c)	Credit Risk Contingent Features

CenterPoint Energy enters into financial derivative contracts containing material adverse change provisions. These provisions could require CenterPoint Energy to post additional collateral if the Standard & Poor’s Ratings Services or Moody’s Investors Service, Inc. credit ratings of CenterPoint Energy, Inc. or its subsidiaries are downgraded. The total fair value of the derivative instruments that contain credit risk contingent features that are in a net liability position at December 31, 2012 and March 31, 2013 was $5 million and $3 million, respectively. The aggregate fair value of assets that were posted as collateral was less than $1 million at both December 31, 2012 and March 31, 2013. If all derivative contracts (in a net liability position) containing credit risk contingent features were triggered at December 31, 2012 and March 31, 2013, $5 million and $2 million, respectively, of additional assets would be required to be posted as collateral.

- Definition

The entire disclosure for the entity's entire derivative instruments and hedging activities. Describes an entity's risk management strategies, derivatives in hedging activities and non-hedging derivative instruments, the assets, obligations, liabilities, revenues and expenses arising therefrom, and the amounts of and methodologies and assumptions used in determining the amounts of such items.

+ References

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+ Details

Fair Value Measurements

3 Months Ended

Mar. 31, 2013

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 generally are exchange-traded derivatives and equity securities.

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 CenterPoint Energy’s Level 2 assets or liabilities.

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 Energy’s judgments about the assumptions market participants would use in pricing the asset or liability since limited market data exists. CenterPoint Energy develops these inputs based on the best information available, including CenterPoint Energy’s own data. A market approach is utilized to value CenterPoint Energy’s Level 3 assets or liabilities. Currently, CenterPoint Energy’s Level 3 assets and liabilities are comprised of physical forward contracts and options. Level 3 physical forward contracts are valued using a discounted cash flow model which includes illiquid forward price curve locations (ranging from $3.71-$4.75 per one million British thermal units) as an unobservable input. Level 3 options are valued through Black-Scholes (including forward start) option models which include option volatilities (ranging from 0-49%) as an unobservable input. CenterPoint Energy’s Level 3 derivative assets and liabilities consist of both long and short positions (forwards and options) and their fair value is sensitive to forward prices and volatilities. If forward prices decrease, CenterPoint Energy’s long forwards lose value whereas its short forwards gain in value. If volatility decreases, CenterPoint Energy’s long options lose value whereas its short options gain in value.

CenterPoint Energy 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 three months ended March 31, 2013, there were no transfers between Level 1 and 2 with regard to Natural Gas derivatives. CenterPoint Energy also recognizes 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 CenterPoint Energy’s assets and liabilities (including derivatives that are presented net) measured at fair value on a recurring basis as of December 31, 2012 and March 31, 2013, and indicate the fair value hierarchy of the valuation techniques utilized by CenterPoint Energy to determine such fair value.



	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Netting Adjustments ⁽¹⁾			Balance as of December 31, 2012
			Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Netting Adjustments ⁽¹⁾			Balance as of December 31, 2012
	(in millions)
Assets
Corporate equities	$	542	$	—	$	—	$	—		$	542
Investments, including money market funds	76		—		—		—			76
Natural gas derivatives	1		40		7		(6		)	42
Total assets	$	619	$	40	$	7	$	(6	)	$	660
Liabilities
Indexed debt securities derivative	$	—	$	268	$	—	$	—		$	268
Natural gas derivatives	5		21		5		(15		)	16
Total liabilities	$	5	$	289	$	5	$	(15	)	$	284

________________


(1)	Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $9 million posted with the same counterparties.



	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Netting Adjustments ⁽¹⁾			Balance as of March 31, 2013
			Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Netting Adjustments ⁽¹⁾			Balance as of March 31, 2013
	(in millions)
Assets
Corporate equities	$	616	$	—	$	—	$	—		$	616
Investments, including money market funds	75		—		—		—			75
Natural gas derivatives	4		23		6		(10		)	23
Total assets	$	695	$	23	$	6	$	(10	)	$	714
Liabilities
Indexed debt securities derivative	$	—	$	319	$	—	$	—		$	319
Natural gas derivatives	2		17		3		(10		)	12
Total liabilities	$	2	$	336	$	3	$	(10	)	$	331

________________


(1)	Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of less than $1 million posted with the same counterparties.

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 has utilized Level 3 inputs to determine fair value:



	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Derivative assets and liabilities, net
	Three Months Ended March 31,
	2012			2013
	(in millions)
Beginning balance	$	6		$	2
Total gains (1)	2			2
Total settlements (1)	(4		)	(1		)
Transfers out of Level 3	(1		)	—
Ending balance (2)	$	3		$	3
The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date	$	—		$	2

________________


(1)	CenterPoint Energy did not have Level 3 unrealized gains (losses) or settlements related to price stabilization activities of the Natural Gas Distribution business segment for either the three months ended March 31, 2012 or 2013.


(2)	During both the three months ended March 31, 2012 and 2013, CenterPoint Energy did not have significant Level 3 purchases, sales or transfers into Level 3.

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 fair values of non-trading derivative assets and liabilities and CenterPoint Energy’s 2.00% Zero-Premium Exchangeable Subordinated Notes due 2029 (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 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.



	December 31, 2012				March 31, 2013
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(in millions)
Financial liabilities:
Long-term debt	$	9,619	$	10,807	$	9,071	$	10,151

- 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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15B
-Subparagraph a, b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 44A, 44B
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15A
-Subparagraph a-d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 11: http://www.xbrl.org/2003/role/presentationRef
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 12: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
-Number 157
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 3, 10, 14, 15
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Midstream Partnership (Notes)	3 Months Ended
Midstream Partnership (Notes)	Mar. 31, 2013
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures Disclosure [Text Block]	Midstream Partnership On March 14, 2013, CenterPoint Energy entered into a Master Formation Agreement with OGE Energy Corp. (OGE) and affiliates of ArcLight Capital Partners, LLC (ArcLight), pursuant to which CenterPoint Energy, OGE and ArcLight agreed to form a midstream partnership (Midstream Partnership) that will initially operate as a private limited partnership. On May 1, 2013, the parties closed on the formation of the Midstream Partnership. In connection with the closing (i) CERC Corp. converted its direct wholly owned subsidiary, CenterPoint Energy Field Services, LLC, a Delaware limited liability company (CEFS), into a Delaware limited partnership that became the Midstream Partnership, (ii) CERC Corp. contributed to the Midstream Partnership its equity interests in each of CenterPoint Energy Gas Transmission Company, LLC (CEGT), CenterPoint Energy - Mississippi River Transmission, LLC (MRT), certain of its other midstream subsidiaries, and a 24.95% interest in Southeast Supply Header, LLC, and (iii) OGE and ArcLight indirectly contributed 100% of the equity interests in Enogex LLC to the Midstream Partnership. The Midstream Partnership is controlled equally by CERC Corp. and OGE.

- 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.

+ References + Details

Goodwill

3 Months Ended

Mar. 31, 2013

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets Disclosure [Text Block]

Goodwill

Goodwill by reportable business segment as of December 31, 2012 and March 31, 2013 was as follows (in millions):



Natural Gas Distribution	$	746
Interstate Pipelines	579
Competitive Natural Gas Sales and Services	83
Field Services	49
Other Operations	11
Total	$	1,468

- 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.

+ References + Details

Capital Stock	3 Months Ended
Capital Stock	Mar. 31, 2013
Class of Stock Disclosures [Abstract]
Capital Stock	Capital Stock CenterPoint Energy, Inc. has 1,020,000,000 authorized shares of capital stock, comprised of 1,000,000,000 shares of $0.01 par value common stock and 20,000,000 shares of $0.01 par value preferred stock. At December 31, 2012, 427,599,730 shares of CenterPoint Energy, Inc. common stock were issued and 427,599,564 shares were outstanding. At March 31, 2013, 428,523,306 shares of CenterPoint Energy, Inc. common stock were issued and 428,523,140 shares were outstanding. Outstanding common shares exclude 166 treasury shares at both December 31, 2012 and March 31, 2013.

- Definition

The entire disclosure for shareholders' equity, comprised of portions attributable to the parent entity and noncontrolling interest, if any, including other comprehensive income (as applicable). Including, but not limited to: (1) balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings; (2) accumulated balance for each classification of other comprehensive income and total amount of comprehensive income; (3) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, and for other comprehensive income, the adjustments for reclassifications to net income; (4) rights and privileges of each class of stock authorized; (5) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (6) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (7) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (8) retained earnings appropriations or restrictions, such as dividend restrictions; (9) impact of change in accounting principle, initial adoption of new accounting principle and correction of an error in previously issued financial statements; (10) shares held in trust for Employee Stock Ownership Plan (ESOP); (11) deferred compensation related to issuance of capital stock; (12) note received for issuance of stock; (13) unamortized discount on shares; (14) description, terms, and number of warrants or rights outstanding; (15) shares under subscription and subscription receivables, effective date of new retained earnings after quasi-reorganization and deficit eliminated by quasi-reorganization and, for a period of at least ten years after the effective date, the point in time from which the new retained dates; and (16) retroactive effective of subsequent change in capital structure.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(d),(e))
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 505
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-Name Accounting Standards Codification
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Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6521494

Reference 12: http://www.xbrl.org/2003/role/presentationRef
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-Section B
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-Chapter 1
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 15: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Principles Board Opinion (APB)
-Number 12
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 16: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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Reference 17: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph d
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Reference 18: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30, 31
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Reference 19: http://www.xbrl.org/2003/role/presentationRef
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-Name Staff Accounting Bulletin (SAB)
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Reference 20: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
-Number 210
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Reference 21: http://www.xbrl.org/2003/role/presentationRef
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Reference 22: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
-Number 129
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Reference 23: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
-Number 210
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+ Details

Short-Term Borrowings and Long-term Debt

3 Months Ended

Mar. 31, 2013

Debt Disclosure [Abstract]

Short-term Borrowings and Long-term Debt [Text Block]

Short-term Borrowings and Long-term Debt


(a)	Short-term Borrowings

Inventory Financing. Gas Operations has asset management agreements associated with its utility distribution service in Arkansas, north Louisiana and Oklahoma that extend through 2015. Pursuant to the provisions of the agreements, Gas Operations sells natural gas and agrees to repurchase an equivalent amount of natural gas during the winter heating seasons at the same cost, plus a financing charge. These transactions are accounted for as a financing and had an associated principal obligation of $38 million and $-0- as of December 31, 2012 and March 31, 2013, respectively.


(b)	Long-term Debt

Credit Facilities. As of December 31, 2012 and March 31, 2013, CenterPoint Energy, CenterPoint Houston and CERC Corp. had the following revolving credit facilities and utilization of such facilities (in millions):



			December 31, 2012						March 31, 2013
	Size of Facility		Loans		Letters of Credit		Commercial Paper		Loans		Letters of Credit		Commercial Paper
CenterPoint Energy	$	1,200	$	—	$	7	$	—	$	—	$	7	$	—
CenterPoint Houston	300		—		4		—		—		4		—
CERC Corp.	950		—		—		—		—		—		61
Total	$	2,450	$	—	$	11	$	—	$	—	$	11	$	61

CenterPoint Energy’s $1.2 billion credit facility, which is scheduled to terminate September 9, 2016, can be drawn at the London Interbank Offered Rate (LIBOR) plus 150 basis points based on CenterPoint Energy’s current credit ratings. The facility contains a debt (excluding transition and system restoration bonds) to earnings before interest, taxes, depreciation and amortization (EBITDA) covenant (as those terms are defined in the facility). The facility allows for a temporary increase of the permitted ratio in the financial covenant from 5 times to 5.5 times if CenterPoint Houston experiences damage from a natural disaster in its service territory and CenterPoint Energy certifies to the administrative agent that CenterPoint Houston has incurred system restoration costs reasonably likely to exceed $100 million in a consecutive twelve-month period, all or part of which CenterPoint Houston intends to seek to recover through securitization financing. Such temporary increase in the financial covenant would be in effect from the date CenterPoint Energy delivers its certification until the earliest to occur of (i) the completion of the securitization financing, (ii) the first anniversary of CenterPoint Energy’s certification or (iii) the revocation of such certification.

CenterPoint Houston’s $300 million credit facility, which is scheduled to terminate September 9, 2016, can be drawn at LIBOR plus 125 basis points based on CenterPoint Houston’s current credit ratings. The facility contains a debt (excluding transition and system restoration bonds) to total capitalization covenant which limits debt to 65% of the borrower’s total capitalization.

CERC Corp.’s $950 million credit facility, which is scheduled to terminate September 9, 2016, can be drawn at LIBOR plus 150 basis points based on CERC Corp.’s current credit ratings. The facility contains a debt to total capitalization covenant which limits debt to 65% of CERC’s total capitalization.

- 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.

+ References + Details

Income Taxes

3 Months Ended

Mar. 31, 2013

Income Tax Disclosure [Abstract]

Income Taxes

The effective tax rate for the three months ended March 31, 2013 was 37%, compared to 33% for the same period in 2012. The lower effective tax rate for the three months ended March 31, 2012 was primarily due to an $11 million reduction to the uncertain tax liability related to a settlement with the Internal Revenue Service (IRS) of CenterPoint Energy's consolidated federal income tax returns for tax years 2006 and 2007.

On January 2, 2013, The American Taxpayer Relief Act of 2012 was signed into law. For CenterPoint Energy, the most significant provision is the extension for one year of the 50 percent bonus depreciation for qualified property. The provision applies to qualified property placed in service before January 1, 2014 (before January 1, 2015, for certain longer-lived and transportation assets). CenterPoint Energy has reflected the effect of the change in tax law in the three months ended March 31, 2013.

The following table summarizes CenterPoint Energy’s unrecognized tax benefits (expenses) at December 31, 2012 and March 31, 2013:



	December 31, 2012			March 31, 2013
	(in millions)
Unrecognized tax expenses	$	(23	)	$	(23	)
Portion of unrecognized tax expenses that, if recognized, would increase the effective income tax rate	(3		)	(3		)
Interest accrued on unrecognized tax expenses	(8		)	(8		)

CenterPoint Energy does not expect the change to the amount of unrecognized tax expenses over the twelve months ending March 31, 2014 to materially impact the financial position of CenterPoint Energy.

CenterPoint Energy's consolidated federal income tax returns have been audited by the IRS and settled through the 2009 tax year. CenterPoint Energy has filed claims for income tax refunds that are pending review by the IRS for tax years 2002, 2003 and 2004. CenterPoint Energy is currently under examination by the IRS for tax years 2010 and 2011. CenterPoint Energy has considered the effects of these examinations in its accrual for settled issues and liability for uncertain income tax positions as of March 31, 2013.

- 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.

+ References

+ Details

Commitments and Contingencies

3 Months Ended

Mar. 31, 2013

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies


(a)	Natural Gas Supply Commitments

Natural gas supply commitments include natural gas contracts related to CenterPoint Energy’s Natural Gas Distribution and Competitive Natural Gas Sales and 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 Condensed Consolidated Balance Sheets as of December 31, 2012 and March 31, 2013 as these contracts meet the exception to be classified 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 March 31, 2013, minimum payment obligations for natural gas supply commitments are approximately $204 million for the remaining nine months in 2013, $328 million in 2014, $219 million in 2015, $152 million in 2016, $99 million in 2017 and $158 million after 2017.


(b)	Long-Term Agreements

Long-term Gas Gathering and Treating Agreements. CEFS has long-term agreements with an indirect wholly owned subsidiary of Encana Corporation (Encana) and an indirect wholly owned subsidiary of Royal Dutch Shell plc (Shell) to provide gathering and treating services for their natural gas production from certain Haynesville Shale and Bossier Shale formations in Texas and Louisiana.

Under the long-term agreements, Encana or Shell may elect to require CEFS to expand the capacity of its gathering systems by up to an additional 1.3 Bcf per day. CEFS estimates that the cost to expand the capacity of its gathering systems by an additional 1.3 Bcf per day would be as much as $440 million. Encana and Shell would provide incremental volume commitments in connection with an election to expand system capacity.

Long-term Agreement with XTO Energy. In March 2013, CenterPoint Energy Bakken Crude Services, LLC (CEBCS), a wholly owned subsidiary of the Midstream Partnership, entered into a long-term agreement with XTO Energy Inc. (XTO), a subsidiary of Exxon Mobil Corporation, to provide gathering services for certain of XTO’s crude oil production through a new crude oil gathering and transportation pipeline system in North Dakota’s liquids-rich Bakken shale. The agreement with XTO was entered into pursuant to the open season announced by CEBCS in February 2013. Under the terms of the agreement, which includes volume commitments, CEBCS will provide service to XTO over a gathering system to be constructed by CEBCS in Dunn and McKenzie counties in North Dakota with a capacity of up to 19,500 barrels per day. CEBCS estimates that the construction of these facilities may cost as much as $125 million.


(c)	Legal, Environmental and Other Regulatory Matters

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 Energy, Inc. (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, nor does it affect the terms of existing guaranty arrangements for certain GenOn gas transportation contracts discussed below.

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’s former affiliate, RRI, was a participant in gas trading in the California and Western markets. These lawsuits, many of which were filed as class actions, allege violations of state and federal antitrust laws. Plaintiffs in these lawsuits are seeking a variety of forms of relief, including, among others, recovery of compensatory damages (in some cases in excess of $1 billion), a trebling of compensatory damages, full consideration damages and attorneys’ fees. CenterPoint Energy and/or Reliant Energy were named in approximately 30 of these lawsuits, which were instituted between 2003 and 2009. CenterPoint Energy and its affiliates have since been released or dismissed from all but two of such cases. CenterPoint Energy Services, Inc. (CES), a subsidiary of CERC 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 FERC jurisdictional sales for resale during the relevant period, based on federal preemption. The plaintiffs appealed this ruling to the United States Court of Appeals for the Ninth Circuit, which reversed the trial court's dismissal of the plaintiffs' claims. The other defendants may seek rehearing en banc before the Ninth Circuit or seek further review by filing a writ of certiorari with the U.S. Supreme Court. Additionally, CenterPoint Energy was a defendant in a lawsuit filed in state court in Nevada that was dismissed in 2007, but in March 2010 the plaintiffs appealed the dismissal to the Nevada Supreme Court. In September 2012, the Nevada Supreme Court affirmed the dismissal. In December 2012, the plaintiffs filed a petition for writ of certiorari with the Supreme Court of the United States. On April 1, 2013, the Supreme Court asked for a reply brief. CenterPoint Energy believes that neither it nor CES is a proper defendant in these remaining cases and will continue to pursue dismissal from those cases. CenterPoint Energy does not expect the ultimate outcome of these remaining matters to have a material impact on its financial condition, results of operations or cash flows.

Natural Gas Measurement Lawsuits. CERC Corp. and certain of its subsidiaries are defendants in two mismeasurement lawsuits brought against approximately 245 pipeline companies and their affiliates pending in state court in Stevens County, Kansas. In one case (originally filed in May 1999 and amended four times), the plaintiffs purport to represent a class of royalty owners who allege that the defendants have engaged in systematic mismeasurement of the volume of natural gas for more than 25 years. The plaintiffs amended their petition in this suit in July 2003 in response to an order from the judge denying certification of the plaintiffs’ alleged class. In the amendment, the plaintiffs dismissed their claims against certain defendants (including two CERC Corp. subsidiaries), limited the scope of the class of plaintiffs they purport to represent and eliminated previously asserted claims based on mismeasurement of the Btu content of the gas. The same plaintiffs then filed a second lawsuit, again as representatives of a putative class of royalty owners in which they assert their claims that the defendants have engaged in systematic mismeasurement of the Btu content of natural gas for more than 25 years. In both lawsuits, the plaintiffs seek compensatory damages, along with statutory penalties, treble damages, interest, costs and fees. In September 2009, the district court in Stevens County, Kansas, denied plaintiffs’ request for class certification of their case and, in March 2010, denied the plaintiffs’ request for reconsideration of that order. The district court subsequently signed an order dismissing without prejudice certain defendants from both lawsuits, including the remaining CenterPoint Energy defendants.

Environmental Matters

Manufactured Gas Plant Sites. CERC and its predecessors operated manufactured gas plants (MGPs) in the past. In Minnesota, CERC has completed remediation on two sites, other than ongoing monitoring and water treatment. There are five remaining sites in CERC’s Minnesota service territory. CERC believes that it has no liability with respect to two of these sites.

At March 31, 2013, CERC had recorded a liability of $13 million for remediation of these Minnesota sites. The estimated range of possible remediation costs for the sites for which CERC believes it may have responsibility was $6 million to $41 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 be dependent upon the number of sites to be remediated, the participation of other potentially responsible parties (PRPs), if any, and the remediation methods used. The Minnesota Public Utilities Commission includes approximately $285,000 annually in rates to fund normal on-going remediation costs. As of March 31, 2013, CERC had collected $5.9 million from insurance companies to be used for future environmental remediation.

In addition to the Minnesota sites, the United States Environmental Protection Agency 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. CERC and CenterPoint Energy do not expect the ultimate outcome of these investigations will have a material adverse impact on the financial condition, results of operations or cash flows of either CenterPoint Energy or CERC.

Asbestos. Some facilities owned by CenterPoint Energy contain or have contained asbestos insulation and other asbestos-containing materials. CenterPoint Energy or its subsidiaries 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 subsidiaries of CenterPoint Energy, but most existing claims relate to facilities previously owned by CenterPoint Energy’s subsidiaries. CenterPoint Energy anticipates that additional claims like those received may be asserted in the future. 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. Although their ultimate outcome cannot be predicted at this time, CenterPoint Energy intends to continue vigorously contesting claims that it does not consider to have merit and, based on its experience to date, does not expect these matters, either individually or in the aggregate, to have a material adverse effect on CenterPoint Energy’s financial condition, results of operations or cash flows.

Other Environmental. From time to time CenterPoint Energy identifies the presence of environmental contaminants on property where its subsidiaries conduct or have conducted operations. Other such sites involving contaminants may be identified in the future. CenterPoint Energy has and expects to continue to remediate identified sites consistent with its legal obligations. From time to time CenterPoint Energy has received notices from regulatory authorities or others regarding its status as a PRP in connection with sites found to require remediation due to the presence of environmental contaminants. In addition, CenterPoint Energy 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 Energy does not expect, based on its experience to date, these matters, either individually or in the aggregate, to have a material adverse effect on CenterPoint Energy’s financial condition, results of operations or cash flows.

Other Proceedings

CenterPoint Energy 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. Some of these proceedings involve substantial amounts. CenterPoint Energy regularly analyzes current information and, as necessary, provides accruals for probable liabilities on the eventual disposition of these matters. CenterPoint Energy does not expect the disposition of these matters to have a material adverse effect on CenterPoint Energy’s financial condition, results of operations or cash flows.


(d)	Guaranties

Prior to the distribution of CenterPoint Energy’s ownership in RRI to its shareholders, CERC had guaranteed certain contractual obligations of what became RRI’s trading subsidiary. When the companies separated, RRI agreed to secure CERC against obligations under the guaranties RRI had been unable to extinguish by the time of separation. Pursuant to such agreement, as amended in December 2007, RRI (now GenOn) agreed to provide to CERC cash or letters of credit as security against CERC’s obligations under its remaining guaranties for demand charges under certain gas transportation agreements if and to the extent changes in market conditions expose CERC to a risk of loss on those guaranties based on an annual calculation, with any required collateral to be posted each December. The undiscounted maximum potential payout of the demand charges under these transportation contracts, which will be in effect until 2018, was approximately $70 million as of March 31, 2013. Based on market conditions in the fourth quarter of 2012 at the time the most recent annual calculation was made under the agreement, GenOn was not obligated to post any security. If GenOn should fail to perform the contractual obligations, CERC could have to honor its guarantee and, in such event, any collateral then provided as security may be insufficient to satisfy CERC’s obligations.

CenterPoint Energy, Inc. has provided guarantees (CenterPoint Midstream Guarantees) with respect to the performance of certain obligations of the Midstream Partnership under long-term gas gathering and treating agreements with Encana and Shell. As of May 1, 2013, CenterPoint Energy, Inc. had guaranteed the Midstream Partnership's obligations up to an aggregate amount of $100 million under these agreements. CERC Corp. has provided guarantees (CERC Midstream Guarantees) with respect to the performance of certain obligations of the Midstream Partnership, CEGT and MRT under certain contractual arrangements with third parties, which guarantees are scheduled to expire between July 2013 and December 2018. The maximum aggregate amount payable by CERC Corp. under these guarantees is $157.2 million. The aggregate dollar amount of the obligations covered by the CERC Midstream Guarantees varies over time. During the month of April 2013, the obligations supported by the CERC Corp. Midstream Guarantees totaled less than $1 million. Under the terms of the omnibus agreement entered into in connection with the closing of the formation of the Midstream Partnership, the Midstream Partnership and CenterPoint Energy, Inc. have agreed to use commercially reasonable efforts and cooperate with each other to terminate the CenterPoint Midstream Guarantees and the CERC Midstream Guarantees, and to release CenterPoint Energy, Inc. or CERC Corp. from such guarantees within 180 days following the formation of the Midstream Partnership by causing the Midstream Partnership or one of its subsidiaries to enter into substitute guarantees or to assume the CenterPoint Midstream Guarantees or CERC Midstream Guarantees, as applicable. CERC Corp. has also provided a guarantee of collection of the Midstream Partnership's obligations under its $1.05 billion 3-year unsecured term loan facility, which guarantee is subordinated to all senior debt of CERC Corp.

- Definition

The entire disclosure for commitments and contingencies.

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+ Details

Earnings Per Share

3 Months Ended

Mar. 31, 2013

Earnings Per Share [Abstract]

Earnings Per Share

The following table reconciles numerators and denominators of CenterPoint Energy’s basic and diluted earnings per share calculations:



	Three Months Ended March 31,
	2012		2013
	(in millions, except share and per share amounts)
Net income	$	147	$	147

Basic weighted average shares outstanding	426,499,000		427,961,000
Plus: Incremental shares from assumed conversions:
Stock options	240,000		100,000
Restricted stock	1,753,000		1,611,000
Diluted weighted average shares	428,492,000		429,672,000

Basic earnings per share:
Net income	$	0.34	$	0.34

Diluted earnings per share:
Net income	$	0.34	$	0.34

Reportable Business Segments

3 Months Ended

Mar. 31, 2013

Segment Reporting [Abstract]

Reportable Business Segments

CenterPoint Energy’s determination of reportable business segments considers the strategic operating units under which CenterPoint Energy manages sales, allocates resources and assesses performance of various products and services to wholesale or retail customers in differing regulatory environments. CenterPoint Energy uses operating income as the measure of profit or loss for its business segments.

CenterPoint Energy’s reportable business segments include the following: Electric Transmission & Distribution, Natural Gas Distribution, Competitive Natural Gas Sales and Services, Interstate Pipelines, Field Services and Other Operations. The electric transmission and distribution function (CenterPoint Houston) is reported in the Electric Transmission & Distribution business segment. Natural Gas Distribution consists of intrastate natural gas sales to, and natural gas transportation and distribution for, residential, commercial, industrial and institutional customers. Competitive Natural Gas Sales and Services represents CenterPoint Energy’s non-rate regulated gas sales and services operations. The Interstate Pipelines business segment includes the interstate natural gas pipeline operations. The Field Services business segment includes the non-rate regulated natural gas gathering, processing and treating operations. Other Operations consists primarily of other corporate operations which support all of CenterPoint Energy’s business operations.

Financial data for business segments are as follows (in millions):



	For the Three Months Ended March 31, 2012
	Revenues from External Customers			Net Intersegment Revenues			Operating Income			Total Assets as of December 31, 2012
Electric Transmission & Distribution	$	531	⁽¹⁾	$	—		$	107		$	11,174
Natural Gas Distribution	849			5			121			4,775
Competitive Natural Gas Sales and Services	520			5			1			839
Interstate Pipelines	82			45			60			4,004
Field Services	99			6			47			2,453
Other Operations	3			—			2			2,600			⁽²⁾
Eliminations	—			(61		)	—			(2,974		)
Consolidated	$	2,084		$	—		$	338		$	22,871

	For the Three Months Ended March 31, 2013
	Revenues from External Customers			Net Intersegment Revenues			Operating Income (Loss)			Total Assets as of March 31, 2013
Electric Transmission & Distribution	$	532	⁽¹⁾	$	—		$	84		$	10,404
Natural Gas Distribution	1,043			8			139			4,734
Competitive Natural Gas Sales and Services	588			9			7			874
Interstate Pipelines	92			40			52			4,039
Field Services	130			11			53			2,450
Other Operations	3			—			(3		)	2,647			⁽²⁾
Eliminations	—			(68		)	—			(2,778		)
Consolidated	$	2,388		$	—		$	332		$	22,370

________________

(1)

Sales to affiliates of NRG in the three months ended March 31, 2012 and 2013 represented approximately $140 million and $144 million, respectively, of CenterPoint Houston’s transmission and distribution revenues. Sales to affiliates of Energy Future Holdings Corp. in both the three months ended March 31, 2012 and 2013 represented approximately $36 million of CenterPoint Houston’s transmission and distribution revenues.


(2)	Included in total assets of Other Operations as of December 31, 2012 and March 31, 2013 are pension and other postemployment related regulatory assets of $832 million and $817 million, respectively.

- 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.

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+ Details

Subsequent Events	3 Months Ended
Subsequent Events	Mar. 31, 2013
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events On April 25, 2013, CenterPoint Energy’s board of directors declared a regular quarterly cash dividend of $0.2075 per share of common stock payable on June 10, 2013, to shareholders of record as of the close of business on May 16, 2013.

Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2013

Compensation and Retirement Disclosure [Abstract]

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

CenterPoint Energy’s net periodic cost includes the following components relating to pension and postretirement benefits:



	Three Months Ended March 31,
	2012						2013
	Pension Benefits(1)			Postretirement Benefits			Pension Benefits(1)			Postretirement Benefits
	(in millions)
Service cost	$	9		$	—		$	11		$	—
Interest cost	25			6			23			5
Expected return on plan assets	(30		)	(2		)	(34		)	(2		)
Amortization of prior service credit	2			1			2			—
Amortization of net loss	15			1			16			2
Amortization of transition obligation	—			2			—			2
Net periodic cost	$	21		$	8		$	18		$	7

________________


(1)	Net periodic cost in these tables is before considering amounts subject to overhead allocations for capital expenditure projects or for amounts subject to deferral for regulatory purposes.

CenterPoint Energy's changes in accumulated comprehensive loss related to defined benefit and postretirement plans are as follows:



	Three Months Ended March 31, 2013
	Pension and Postretirement Plans
	(in millions)

Beginning Balance	$	(132	)
Amounts reclassified from accumulated other comprehensive income:
Prior service cost (1)	1
Actuarial gains (1)	4
Total reclassifications from accumulated other comprehensive income	5
Tax expense	(2		)
Net current period other comprehensive income	3
Ending Balance	$	(129	)

________________


(1)	These accumulated other comprehensive components are included in the computation of net periodic cost.

- 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.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e2410-114920

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=21916443&loc=d3e4179-114921

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 158
-Paragraph 4, 7, 16, 20, 21
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5, 6, 7
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Derivative Instruments (Tables)

3 Months Ended

Mar. 31, 2013

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Fair Value of Derivative Instruments Table



Fair Value of Derivative Instruments
		December 31, 2012
Total derivatives not designated as hedging instruments	Balance Sheet Location	Derivative Assets Fair Value		Derivative Liabilities Fair Value
		(in millions)
Natural gas derivatives (1) (2)	Current Assets: Non-trading derivative assets	$	37	$	1
Natural gas derivatives (1) (2)	Other Assets: Non-trading derivative assets	6		—
Natural gas derivatives (1) (2)	Current Liabilities: Non-trading derivative liabilities	5		27
Natural gas derivatives (1) (2)	Other Liabilities: Non-trading derivative liabilities	1		4
Indexed debt securities derivative	Current Liabilities	—		268
Total		$	49	$	300

________________


(1)	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 489 billion cubic feet (Bcf) or a net 101 Bcf long position. Of the net long position, basis swaps constitute 73 Bcf.

(2)



Offsetting of Natural Gas Derivative Assets and Liabilities
	December 31, 2012
	Gross Amounts Recognized (1)			Gross Amounts Offset in the Consolidated Balance Sheets			Net Amount Presented in the Consolidated Balance Sheets (2)
	(in millions)
Current Assets: Non-trading derivative assets	$	42		$	(6	)	$	36
Other Assets: Non-trading derivative assets	7			(1		)	6
Current Liabilities: Non-trading derivative liabilities	(28		)	14			(14		)
Other Liabilities: Non-trading derivative liabilities	(4		)	2			(2		)
Total	$	17		$	9		$	26

________________


(1)	Gross Amounts Recognized contain some derivative assets and liabilities that are not subject to master netting arrangements.


(2)	The derivative assets and liabilities on the Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default.



Fair Value of Derivative Instruments
		March 31, 2013
Total derivatives not designated as hedging instruments	Balance Sheet Location	Derivative Assets Fair Value		Derivative Liabilities Fair Value
		(in millions)
Natural gas derivatives (1) (2)	Current Assets: Non-trading derivative assets	$	26	$	8
Natural gas derivatives (1) (2)	Other Assets: Non-trading derivative assets	5		1
Natural gas derivatives (1) (2)	Current Liabilities: Non-trading derivative liabilities	1		11
Natural gas derivatives (1) (2)	Other Liabilities: Non-trading derivative liabilities	1		2
Indexed debt securities derivative	Current Liabilities	—		319
Total		$	33	$	341

________________


(1)	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 492 Bcf or a net 107 Bcf long position. Of the net long position, basis swaps constitute 57 Bcf.

(2)

Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was an $11 million asset as shown on CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of less than $1 million:



Offsetting of Natural Gas Derivative Assets and Liabilities
	March 31, 2013
	Gross Amounts Recognized (1)			Gross Amounts Offset in the Consolidated Balance Sheets			Net Amount Presented in the Consolidated Balance Sheets (2)
	(in millions)
Current Assets: Non-trading derivative assets	$	27		$	(9	)	$	18
Other Assets: Non-trading derivative assets	6			(1		)	5
Current Liabilities: Non-trading derivative liabilities	(19		)	9			(10		)
Other Liabilities: Non-trading derivative liabilities	(3		)	1			(2		)
Total	$	11		$	—		$	11

________________


(1)	Gross Amounts Recognized contain some derivative assets and liabilities that are not subject to master netting arrangements.


(2)	The derivative assets and liabilities on the Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default.

Income Statement Impact of Derivative Activity Table



Income Statement Impact of Derivative Activity
		Three Months Ended March 31,
Total derivatives not designated as hedging instruments	Income Statement Location	2012			2013
		(in millions)
Natural gas derivatives	Gains (Losses) in Revenue	$	51		$	(14	)
Natural gas derivatives (1)	Gains (Losses) in Expense: Natural Gas	(81		)	16
Indexed debt securities derivative	Gains (Losses) in Other Income (Expense)	(33		)	(51		)
Total		$	(63	)	$	(49	)

________________


(1)	The Gains (Losses) in Expense: Natural Gas includes $(38) million and $-0- of costs in 2012 and 2013, respectively, associated with price stabilization activities of the Natural Gas Distribution business segment that will be ultimately recovered through purchased gas adjustments.

- Definition

Tabular disclosure of the location and amount of gains and losses reported in the statement of financial performance, or when applicable, the statement of financial position. For example, (a) gains and losses recognized in the income statement on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges and (b) gains and losses initially recognized in other comprehensive income on derivative instruments designated and qualifying as cash flow hedges.

+ References + Details

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2013

Fair Value Disclosures [Abstract]

Fair value, assets measured on a recurring basis



	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Netting Adjustments ⁽¹⁾			Balance as of December 31, 2012
			Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Netting Adjustments ⁽¹⁾			Balance as of December 31, 2012
	(in millions)
Assets
Corporate equities	$	542	$	—	$	—	$	—		$	542
Investments, including money market funds	76		—		—		—			76
Natural gas derivatives	1		40		7		(6		)	42
Total assets	$	619	$	40	$	7	$	(6	)	$	660
Liabilities
Indexed debt securities derivative	$	—	$	268	$	—	$	—		$	268
Natural gas derivatives	5		21		5		(15		)	16
Total liabilities	$	5	$	289	$	5	$	(15	)	$	284

________________


(1)	Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $9 million posted with the same counterparties.



	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Netting Adjustments ⁽¹⁾			Balance as of March 31, 2013
			Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Netting Adjustments ⁽¹⁾			Balance as of March 31, 2013
	(in millions)
Assets
Corporate equities	$	616	$	—	$	—	$	—		$	616
Investments, including money market funds	75		—		—		—			75
Natural gas derivatives	4		23		6		(10		)	23
Total assets	$	695	$	23	$	6	$	(10	)	$	714
Liabilities
Indexed debt securities derivative	$	—	$	319	$	—	$	—		$	319
Natural gas derivatives	2		17		3		(10		)	12
Total liabilities	$	2	$	336	$	3	$	(10	)	$	331

________________


(1)	Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of less than $1 million posted with the same counterparties.

Assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs



	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Derivative assets and liabilities, net
	Three Months Ended March 31,
	2012			2013
	(in millions)
Beginning balance	$	6		$	2
Total gains (1)	2			2
Total settlements (1)	(4		)	(1		)
Transfers out of Level 3	(1		)	—
Ending balance (2)	$	3		$	3
The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date	$	—		$	2

________________


(1)	CenterPoint Energy did not have Level 3 unrealized gains (losses) or settlements related to price stabilization activities of the Natural Gas Distribution business segment for either the three months ended March 31, 2012 or 2013.


(2)	During both the three months ended March 31, 2012 and 2013, CenterPoint Energy did not have significant Level 3 purchases, sales or transfers into Level 3.

Estimated fair value of financial instruments, debt instruments



	December 31, 2012				March 31, 2013
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(in millions)
Financial liabilities:
Long-term debt	$	9,619	$	10,807	$	9,071	$	10,151

- Definition

Tabular disclosure of assets, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, by class 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).

+ References + Details

- 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.

+ References + Details

- Definition

Tabular disclosure of the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments, assets, and liabilities. Such certain disclosures about the financial instruments, assets, and liabilities include: (1) the fair value of the required items together with their carrying amounts (as appropriate) and (2) the methodology and assumptions used in developing such estimates of fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13476-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13467-108611

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6447952&loc=d3e13220-108610

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13433-108611

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 19
-Subparagraph a, b, c(1), d(1)
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 14
-Subparagraph a
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15
-Subparagraph b-d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 18
-Subparagraph c(2), d, e, f
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32
-Subparagraph a, c(1), c(2), c(3), d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Goodwill (Tables)

3 Months Ended

Mar. 31, 2013

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill [Table Text Block]

Goodwill by reportable business segment as of December 31, 2012 and March 31, 2013 was as follows (in millions):



Natural Gas Distribution	$	746
Interstate Pipelines	579
Competitive Natural Gas Sales and Services	83
Field Services	49
Other Operations	11
Total	$	1,468

- Definition

Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.

+ References + Details

Short-Term Borrowings and Long-term Debt Credit Facilities (Tables)

3 Months Ended

Mar. 31, 2013

Debt Disclosure [Abstract]

Schedule of Line of Credit Facilities [Table Text Block]



			December 31, 2012						March 31, 2013
	Size of Facility		Loans		Letters of Credit		Commercial Paper		Loans		Letters of Credit		Commercial Paper
CenterPoint Energy	$	1,200	$	—	$	7	$	—	$	—	$	7	$	—
CenterPoint Houston	300		—		4		—		—		4		—
CERC Corp.	950		—		—		—		—		—		61
Total	$	2,450	$	—	$	11	$	—	$	—	$	11	$	61

Income Taxes (Tables)

3 Months Ended

Mar. 31, 2013

Income Tax Disclosure [Abstract]

Summary of unrecognized tax benefits

The following table summarizes CenterPoint Energy’s unrecognized tax benefits (expenses) at December 31, 2012 and March 31, 2013:



	December 31, 2012			March 31, 2013
	(in millions)
Unrecognized tax expenses	$	(23	)	$	(23	)
Portion of unrecognized tax expenses that, if recognized, would increase the effective income tax rate	(3		)	(3		)
Interest accrued on unrecognized tax expenses	(8		)	(8		)

- Definition

Tabular disclosure of tax positions taken in the tax returns filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities (i.e., uncertain tax positions) and other types of income tax contingencies, including: (1) the policy on classification of interest and penalties; (2) a tabular reconciliation of the total amounts of unrecognized tax benefits at the beginning and end of the period; the total amount(s) of: (3) unrecognized tax benefits that, if recognized, would affect the effective tax rate, and (4) interest and penalties recognized in each of the income statement and balance sheet; (5) for positions for which it is reasonably possible that the total amounts unrecognized will significantly change within 12 months of the reporting date the: (i) nature of the uncertainty, (ii) nature of the event that could occur that would cause the change, and (iii) an estimate of the range of the reasonably possible change or a statement that an estimate of the range cannot be made; and (6) a description of tax years that remain subject to examination by major tax jurisdictions.

+ References + Details

Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2013

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:



	Three Months Ended March 31,
	2012		2013
	(in millions, except share and per share amounts)
Net income	$	147	$	147

Basic weighted average shares outstanding	426,499,000		427,961,000
Plus: Incremental shares from assumed conversions:
Stock options	240,000		100,000
Restricted stock	1,753,000		1,611,000
Diluted weighted average shares	428,492,000		429,672,000

Basic earnings per share:
Net income	$	0.34	$	0.34

Diluted earnings per share:
Net income	$	0.34	$	0.34

Reportable Business Segments (Tables)

3 Months Ended

Mar. 31, 2013

Segment Reporting [Abstract]

Financial data for business segments

Financial data for business segments are as follows (in millions):



	For the Three Months Ended March 31, 2012
	Revenues from External Customers			Net Intersegment Revenues			Operating Income			Total Assets as of December 31, 2012
Electric Transmission & Distribution	$	531	⁽¹⁾	$	—		$	107		$	11,174
Natural Gas Distribution	849			5			121			4,775
Competitive Natural Gas Sales and Services	520			5			1			839
Interstate Pipelines	82			45			60			4,004
Field Services	99			6			47			2,453
Other Operations	3			—			2			2,600			⁽²⁾
Eliminations	—			(61		)	—			(2,974		)
Consolidated	$	2,084		$	—		$	338		$	22,871

	For the Three Months Ended March 31, 2013
	Revenues from External Customers			Net Intersegment Revenues			Operating Income (Loss)			Total Assets as of March 31, 2013
Electric Transmission & Distribution	$	532	⁽¹⁾	$	—		$	84		$	10,404
Natural Gas Distribution	1,043			8			139			4,734
Competitive Natural Gas Sales and Services	588			9			7			874
Interstate Pipelines	92			40			52			4,039
Field Services	130			11			53			2,450
Other Operations	3			—			(3		)	2,647			⁽²⁾
Eliminations	—			(68		)	—			(2,778		)
Consolidated	$	2,388		$	—		$	332		$	22,370

________________

(1)


(2)	Included in total assets of Other Operations as of December 31, 2012 and March 31, 2013 are pension and other postemployment related regulatory assets of $832 million and $817 million, respectively.

- 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.

+ References + Details

Background and Basis of Presentation (Details)	Mar. 31, 2013
Number Of Vies Consolidated In Financial Statements	5

Employee Benefit Plans (Details) - USD ($)
$ in Millions

1 Months Ended

3 Months Ended

Apr. 30, 2013

Mar. 31, 2013

Mar. 31, 2012

Defined Benefit Plan, Change in Accumulated Comprehensive Loss [Roll Forward]

Beginning Balance

$ (132)

$ (135)

Amounts reclassified from accumulated other comprehensive income: [Abstract]

Net current period other comprehensive income

$ 2

Ending Balance

(132)

Other Pension Plans, Postretirement or Supplemental Plans, Defined Benefit [Member]

Defined Benefit Plan, Change in Accumulated Comprehensive Loss [Roll Forward]

Beginning Balance

(129)

(132)

Amounts reclassified from accumulated other comprehensive income: [Abstract]

Prior service cost

^[1]

Actuarial gains

^[1]

Total reclassifications from accumulated other comprehensive income

Tax expense

(2)

Net current period other comprehensive income

Ending Balance

(129)

Pension Plans, Defined Benefit [Member]

Defined Benefit Plan Disclosure [Line Items]

Service cost

^[2]

Interest cost

^[2]

Expected return on plan assets

^[2]

(34)

(30)

Amortization of prior service credit

^[2]

Amortization of net loss

^[2]

Amortization of transition obligation

^[2]

Net periodic cost

^[2]

Total contributions to the plans during the period

$ 27

Total contributions expected in 2013

Other Postretirement Benefit Plans, Defined Benefit [Member]

Defined Benefit Plan Disclosure [Line Items]

Service cost

Interest cost

Expected return on plan assets

(2)

Amortization of prior service credit

Amortization of net loss

Amortization of transition obligation

Net periodic cost

$ 8

Total contributions to the plans during the period

Total contributions expected in 2013

$ 17

[1]	These accumulated other comprehensive components are included in the computation of net periodic cost.
[2]	Net periodic cost in these tables is before considering amounts subject to overhead allocations for capital expenditure projects or for amounts subject to deferral for regulatory purposes.

Regulatory Accounting (Details) - USD ($) $ in Millions	3 Months Ended
Regulatory Accounting (Details) - USD ($) $ in Millions	Mar. 31, 2013	Mar. 31, 2012
Amount of allowed equity return on the true-up balance that has not been recognized	$ 545
Amount of allowed equity return on the true-up balance that was recognized in the period	$ 8	$ 8

Derivative Instruments (Details)
MMcf in Thousands, $ in Millions

3 Months Ended

12 Months Ended

Mar. 31, 2013

USD ($)

MMcf

Mar. 31, 2012

USD ($)

Dec. 31, 2012

USD ($)

MMcf

Derivative, Fair Value, Net [Abstract]

Derivative assets fair value

$ 33

^[1],[2]

$ 49

^[3],[4]

Derivative liabilities fair value

$ 341

^[1],[2]

$ 300

^[3],[4]

Derivative gross volumes on natural gas contracts (MMcf) | MMcf

492

489

Net long position (MMcf) | MMcf

107

101

Amount of net long position constituted by basis swaps (MMcf) | MMcf

Gross Amounts Recognized

^[5]

$ 11

$ 17

Gross Amounts Offset in the Consolidated Balance Sheets

Net Amount Presented in the Consolidated Balance Sheets

^[6]

Total fair value of the derivative instruments that contain credit risk contingent features that are in a net liability position

The aggregate fair value of assets already posted as collateral

Credit Risk Contingent Features assets

$ 2

Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]

Term of normal weather used as the basis for weather hedges (in years)

Gains (Losses) Recognized Related to Weather Hedges

$ (3)

$ 6

Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net

(49)

(63)

Collateral netting offsetting natural gas derivative assets and liabilities

Current Assets [Member]

Derivative, Fair Value, Net [Abstract]

Gross Amounts Recognized

^[5]

Gross Amounts Offset in the Consolidated Balance Sheets

(9)

(6)

Net Amount Presented in the Consolidated Balance Sheets

^[6]

Other Assets [Member]

Derivative, Fair Value, Net [Abstract]

Gross Amounts Recognized

^[5]

Gross Amounts Offset in the Consolidated Balance Sheets

(1)

Net Amount Presented in the Consolidated Balance Sheets

^[6]

Current Liabilities [Member]

Derivative, Fair Value, Net [Abstract]

Gross Amounts Recognized

^[5]

(19)

(28)

Gross Amounts Offset in the Consolidated Balance Sheets

Net Amount Presented in the Consolidated Balance Sheets

^[6]

(10)

(14)

Other Liabilities [Member]

Derivative, Fair Value, Net [Abstract]

Gross Amounts Recognized

^[5]

(3)

(4)

Gross Amounts Offset in the Consolidated Balance Sheets

Net Amount Presented in the Consolidated Balance Sheets

^[6]

(2)

Natural Gas Derivatives [Member] | Gains (Losses) in Revenue [Member]

Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]

Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net

(14)

Natural Gas Derivatives [Member] | Gains (Losses) in Expense: Natural Gas [Member]

Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]

Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net

^[7]

(81)

Costs associated with price stabilization activities of the Natural Gas Distribution business segment included in Expenses

(38)

Indexed Debt Securities Derivative [Member] | Gains (losses) in Other Income (Expense) [Member]

Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]

Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net

(51)

$ (33)

Not Designated as Hedging Instrument [Member] | Natural Gas Derivatives [Member] | Current Assets [Member]

Derivative, Fair Value, Net [Abstract]

Derivative assets fair value

^[1],[2]

^[3],[4]

Derivative liabilities fair value

^[1],[2]

^[3],[4]

Not Designated as Hedging Instrument [Member] | Natural Gas Derivatives [Member] | Other Assets [Member]

Derivative, Fair Value, Net [Abstract]

Derivative assets fair value

^[1],[2]

^[3],[4]

Derivative liabilities fair value

^[1],[2]

^[3],[4]

Not Designated as Hedging Instrument [Member] | Natural Gas Derivatives [Member] | Current Liabilities [Member]

Derivative, Fair Value, Net [Abstract]

Derivative assets fair value

^[1],[2]

^[3],[4]

Derivative liabilities fair value

^[1],[2]

^[3],[4]

Not Designated as Hedging Instrument [Member] | Natural Gas Derivatives [Member] | Other Liabilities [Member]

Derivative, Fair Value, Net [Abstract]

Derivative assets fair value

^[1],[2]

^[3],[4]

Derivative liabilities fair value

^[1],[2]

^[3],[4]

Not Designated as Hedging Instrument [Member] | Indexed Debt Securities Derivative [Member] | Current Liabilities [Member]

Derivative, Fair Value, Net [Abstract]

Derivative assets fair value

Derivative liabilities fair value

$ 319

$ 268

[1]	Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was an $11 million asset as shown on CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of less than $1 million
[2]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 492 Bcf or a net 107 Bcf long position. Of the net long position, basis swaps constitute 57 Bcf.
[3]	Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was a $26 million asset as shown on CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $9 million:
[4]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 489 billion cubic feet (Bcf) or a net 101 Bcf long position. Of the net long position, basis swaps constitute 73 Bcf.
[5]	Gross Amounts Recognized contain some derivative assets and liabilities that are not subject to master netting arrangements.
[6]	The derivative assets and liabilities on the Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default.
[7]	The Gains (Losses) in Expense: Natural Gas includes $(38) million and $-0- of costs in 2012 and 2013, respectively, associated with price stabilization activities of the Natural Gas Distribution business segment that will be ultimately recovered through purchased gas adjustments.

Fair Value Measurements (Details) - USD ($)

3 Months Ended

Mar. 31, 2013

Mar. 31, 2012

Dec. 31, 2012

Assets

Corporate equities

$ 616,000,000

$ 542,000,000

Investments, including money market funds

75,000,000

76,000,000

Natural gas derivatives, assets

23,000,000

42,000,000

Total assets

714,000,000

660,000,000

Liabilities

Indexed debt securities derivative

319,000,000

268,000,000

Natural gas derivatives, liabilities

12,000,000

16,000,000

Total liabilities

331,000,000

284,000,000

Cash collateral posted with counterparties

1,000,000

9,000,000

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]

Beginning balance

2,000,000

$ 6,000,000

Total gains

^[1]

2,000,000

Total settlements

^[1]

(1,000,000)

(4,000,000)

Transfers out of Level 3

(1,000,000)

Ending balance

^[2]

3,000,000

The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date

2,000,000

$ 0

Carrying Amount [Member]

Liabilities

Long-term Debt

9,071,000,000

9,619,000,000

Fair Value [Member]

Liabilities

Long-term Debt

10,151,000,000

10,807,000,000

Fair Value, Inputs, Level 1 [Member]

Assets

Corporate equities

616,000,000

542,000,000

Investments, including money market funds

75,000,000

76,000,000

Natural gas derivatives, assets

4,000,000

1,000,000

Total assets

695,000,000

619,000,000

Liabilities

Indexed debt securities derivative

Natural gas derivatives, liabilities

2,000,000

5,000,000

Total liabilities

2,000,000

5,000,000

Fair Value, Inputs, Level 2 [Member]

Assets

Corporate equities

Investments, including money market funds

Natural gas derivatives, assets

23,000,000

40,000,000

Total assets

23,000,000

40,000,000

Liabilities

Indexed debt securities derivative

319,000,000

268,000,000

Natural gas derivatives, liabilities

17,000,000

21,000,000

Total liabilities

336,000,000

289,000,000

Fair Value, Inputs, Level 3 [Member]

Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]

Illiquid forward price low range (per mmbtu)

3.71

Illiquid forward price high range (per mmbtu)

$ 4.75

Option volatilities low range

0.00%

Option volatilities high range

49.00%

Assets

Corporate equities

$ 0

Investments, including money market funds

Natural gas derivatives, assets

6,000,000

7,000,000

Total assets

6,000,000

7,000,000

Liabilities

Indexed debt securities derivative

Natural gas derivatives, liabilities

3,000,000

5,000,000

Total liabilities

3,000,000

5,000,000

Netting Adjustments [Member]

Assets

Corporate equities

^[3]

^[4]

Investments, including money market funds

^[3]

^[4]

Natural gas derivatives, assets

(10,000,000)

^[3]

(6,000,000)

^[4]

Total assets

(10,000,000)

^[3]

(6,000,000)

^[4]

Liabilities

Indexed debt securities derivative

^[3]

^[4]

Natural gas derivatives, liabilities

(10,000,000)

^[3]

(15,000,000)

^[4]

Total liabilities

$ (10,000,000)

^[3]

$ (15,000,000)

^[4]

[1]	CenterPoint Energy did not have Level 3 unrealized gains (losses) or settlements related to price stabilization activities of the Natural Gas Distribution business segment for either the three months ended March 31, 2012 or 2013.
[2]	During both the three months ended March 31, 2012 and 2013, CenterPoint Energy did not have significant Level 3 purchases, sales or transfers into Level 3.
[3]	Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of less than $1 million posted with the same counterparties.
[4]	Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $9 million posted with the same counterparties.

Midstream Partnership (Details)	1 Months Ended
Midstream Partnership (Details)	Apr. 30, 2013
Southeast Supply Header Llc [Member] \| CERC Corp [Member]
Equity Interest Contributed, Percentage	24.95%
Enogex LLC [Member] \| OGE ARCLIGHT [Member]
Equity Interest Contributed, Percentage	100.00%

Goodwill (Details) - USD ($) $ in Millions	Mar. 31, 2013	Dec. 31, 2012
Goodwill Schedule [Line Items]
Goodwill	$ 1,468	$ 1,468
Natural Gas Distribution [Member]
Goodwill Schedule [Line Items]
Goodwill	746	746
Interstate Pipelines [Member]
Goodwill Schedule [Line Items]
Goodwill	579	579
Competitive Natural Gas Sales and Services [Member]
Goodwill Schedule [Line Items]
Goodwill	83	83
Field Services [Member]
Goodwill Schedule [Line Items]
Goodwill	49	49
Corporate and Other [Member]
Goodwill Schedule [Line Items]
Goodwill	$ 11	$ 11

- Definition

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 45
-Subparagraph e
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 43
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141R
-Paragraph 72
-Subparagraph d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 142
-Paragraph 45
-Subparagraph e
-Clause 1
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141R
-Paragraph 68
-Subparagraph l
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141R
-Paragraph 34
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Capital Stock (Details) - $ / shares	Mar. 31, 2013	Dec. 31, 2012
Class of Stock Disclosures [Abstract]
Capital stock shares authorized (in shares)	1,020,000,000
Common stock shares authorized (in shares)	1,000,000,000
Common stock shares par value (in dollars per share)	$ 0.01
Cumulative preferred stock shares authorized (in shares)	20,000,000
Cumulative preferred stock par value (in dollars per share)	$ 0.01
Total common stock issued (in shares)	428,523,306	427,599,730
Total common stock outstanding (in shares)	428,523,140	427,599,564
Treasury stock (in shares)	166	166

Short-Term Borrowings and Long-term Debt (Details) $ in Millions	3 Months Ended
	Mar. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Debt Instrument [Line Items]
Total short term borrowings	$ 0	$ 38
Long-term Debt [Abstract]
Total credit facility amount	2,450	2,450
Loans Outstanding	0	0
Letters of Credit outstanding	11	11
Commercial Paper Outstanding	61	0
Bank loans due 2016 [Member] \| CenterPoint Houston [Member]
Long-term Debt [Abstract]
Total credit facility amount	300	300
Loans Outstanding	0	0
Letters of Credit outstanding	4	4
Commercial Paper Outstanding	$ 0	0
Revolving credit facility borrowing rate	LIBOR plus 125
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	65.00%
Bank loans due 2016 [Member] \| CenterPoint Energy [Member]
Long-term Debt [Abstract]
Total credit facility amount	$ 1,200	1,200
Loans Outstanding	0	0
Letters of Credit outstanding	7	7
Commercial Paper Outstanding	$ 0	0
Revolving credit facility borrowing rate	London Interbank Offered Rate (LIBOR) plus 150
Debt to EBITDA covenant ratio, before amendment	5
Debt to EBITDA covenant ratio, amendment	5.5
System restoration costs threshold for increase in permitted debt to EBITDA covenant ratio	$ 100
Consecutive Period for System Restoration Costs to Exceed $100 million (in months)	12
Bank loans due 2016 [Member] \| CERC Corp [Member]
Long-term Debt [Abstract]
Total credit facility amount	$ 950	950
Loans Outstanding	0	0
Letters of Credit outstanding	0	0
Commercial Paper Outstanding	$ 61	0
Revolving credit facility borrowing rate	LIBOR plus 150
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	65.00%
Product Financing Arrangement [Member]
Debt Instrument [Line Items]
Total short term borrowings	$ 0	$ 38

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Effective tax rate (in hundredths)	37.00%	33.00%
Unrecognized tax expenses	$ (23)		$ (23)
Portion of unrecognized tax expenses that, if recognized, would increase the effective income tax rate	(3)		(3)
Interest accrued on unrecognized tax expenses	$ (8)		$ (8)
Period of time for possible impact of unrecognized tax expenses (in months)	12
Tax Adjustments, Settlements, and Unusual Provisions		$ 11
Period of time extended under the American Taxpayer Relief Act of 2012	1 year
Depreciation Bonus for qualified long-lived assets under American Taxpayer Relief Act of 2012	50.00%

Commitments and Contingencies (Details)	1 Months Ended	3 Months Ended
Commitments and Contingencies (Details)	Apr. 30, 2013 USD ($)	Mar. 31, 2013 USD ($) bbl MMcf	May 01, 2013 USD ($)
Recorded Unconditional Purchase Obligation
2013		$ 204,000,000
2014		328,000,000
2015		219,000,000
2016		152,000,000
2017		99,000,000
After 2017		$ 158,000,000
Legal Environmental And Other Regulatory Matters
Recovery of compensatory damages sought by plaintiffs		in excess of $1 billion
Approximate number of gas market manipulation lawsuits naming CenterPoint and/or Reliant Energy (in number of lawsuits)		30
Number of gas market manipulation lawsuits pending for CenterPoint and its affiliates (in number of lawsuits)		2
Number of gas market mismeasurement lawsuits pending for CenterPoint and its affiliates (in number of lawsuits)		2
Approximate number of pipeline companies named in the mismeasurement lawsuits (in number of companies)		245
Number of gas measurement lawsuits seeking class certification and has four amendments (in number of cases)		1
Number of times gas measurement lawsuit was amended (in number of amendments)		4
Number of years the plaintiffs claim the defendants have engaged in the systematic mismeasurement of natural gas (in years)		25
Number of CenterPoint subsidiaries dismissed from the claims of the plaintiff (in number of claims)		2
Number of sites where remediation is complete, other than ongoing operations (in number of sites)		2
Number of remaining sites in the Minnesota service territory (in number of sites)		5
Number of the remaining sites in the Minnesota service territory where the company believes it has no liability (in number of sites)		2
Amount accrued for remediation of Minnesota sites (in number of sites)		$ 13,000,000
Minimum estimated remediation costs for the Minnesota sites		6,000,000
Maximum estimated remediation costs for the Minnesota sites		$ 41,000,000
Minimum years of remediation for the Minnesota sites (in years)		30
Maximum years of remediation for the Minnesota sites (in years)		50
Annual amount included in rates to fund normal on-going remediation costs		$ 285,000
Amount collected from insurance companies to be used for future environmental remediation		5,900,000
Approximate amount of undiscounted maximum obligation under guarantee		$ 70,000,000
Long-Term Gas Gathering and Treating Agreements [Member]
Schedule of Capital Expansion Projects
Total capacity per day of system after potential additional expansion (in MMcf) \| MMcf		1,300
Estimated Total Capital Expenditures For Expansion		$ 440,000,000
Long-term Agreement with XTO Energy [Member]
Schedule of Capital Expansion Projects
Capacity upon construction of gathering and transportation pipeline system (barrels per day) \| bbl		19,500
Estimated construction costs of gathering and transportation pipeline system		$ 125,000,000
CenterPoint Energy [Member]
Legal Environmental And Other Regulatory Matters
Guarantee Obligations Maximum Amount Upon Completion Of Gathering Systems			$ 100,000,000
CERC Corp [Member]
Legal Environmental And Other Regulatory Matters
Approximate amount of undiscounted maximum obligation under guarantee			157,200,000
Guarantor Obligations, Current Amount	$ 1,000,000
Midstream Partnership [Member]
Legal Environmental And Other Regulatory Matters
Unsecured Debt			$ 1,050,000,000
Debt Instrument, Description	3-year

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net income	$ 147	$ 147
Basic weighted average shares outstanding	427,961,000	426,499,000
Plus: Incremental shares from assumed conversions:
Stock Options	100,000	240,000
Restricted Stock	1,611,000	1,753,000
Diluted weighted average shares	429,672,000	428,492,000
Basic Earnings Per Share:
Net income	$ 0.34	$ 0.34
Diluted earnings per share:
Net income	$ 0.34	$ 0.34

Reportable Business Segments (Details) - USD ($)
$ in Millions

3 Months Ended

Mar. 31, 2013

Mar. 31, 2012

Dec. 31, 2012

Segment Reporting Information [Line Items]

Revenues from External Customers

$ 2,388

$ 2,084

Net Intersegment Revenues

Operating Income (Loss)

332

338

Total Assets

22,370

$ 22,871

Electric Transmission and Distribution [Member]

Segment Reporting Information [Line Items]

Revenue from External Customers

^[1]

532

531

Net Intersegment Revenues

Operating Income (Loss)

107

Total Assets

10,404

11,174

Natural Gas Distribution [Member]

Segment Reporting Information [Line Items]

Revenue from External Customers

1,043

849

Net Intersegment Revenues

Operating Income (Loss)

139

121

Total Assets

4,734

4,775

Competitive Natural Gas Sales and Services [Member]

Segment Reporting Information [Line Items]

Revenue from External Customers

588

520

Net Intersegment Revenues

Operating Income (Loss)

Total Assets

874

839

Interstate Pipelines [Member]

Segment Reporting Information [Line Items]

Revenue from External Customers

Net Intersegment Revenues

Operating Income (Loss)

Total Assets

4,039

4,004

Field Services [Member]

Segment Reporting Information [Line Items]

Revenue from External Customers

130

Net Intersegment Revenues

Operating Income (Loss)

Total Assets

2,450

2,453

Other Operations [Member]

Segment Reporting Information [Line Items]

Revenue from External Customers

Net Intersegment Revenues

Operating Income (Loss)

(3)

Total Assets

^[2]

2,647

2,600

Pension and other postemployment related regulatory assets included in total assets of Other Operations

817

832

Eliminations [Member]

Segment Reporting Information [Line Items]

Revenue from External Customers

Net Intersegment Revenues

(68)

(61)

Operating Income (Loss)

Total Assets

(2,778)

$ (2,974)

Affiliates of NRG Energy, Inc. [Member] | Electric Transmission and Distribution [Member]

Segment Reporting Information [Line Items]

Revenues from major customers

144

140

Affiliates of Energy Future Holdings Corp. [Member] | Electric Transmission and Distribution [Member]

Segment Reporting Information [Line Items]

Revenues from major customers

$ 36

[1]

[2]

Included in total assets of Other Operations as of December 31, 2012 and March 31, 2013 are pension and other postemployment related regulatory assets of $832 million and $817 million, respectively.

Subsequent Events (Details) - Dividend Declared [Member]	1 Months Ended
	Apr. 30, 2013 USD ($)
Subsequent Event [Line Items]
Subsequent Event, Date	Apr. 25, 2013
Subsequent Event, Amount	$ 0.2075
Dividends Payable, Date to be Paid, Day, Month and Year	Jun. 10, 2013
Dividends Payable, Date of Record, Day, Month and Year	May 16, 2013