View Filing Data

Document And Entity Information - USD ($) $ in Millions	6 Months Ended
Document And Entity Information - USD ($) $ in Millions	Jun. 30, 2012	Jul. 16, 2012	Jun. 30, 2011
Document and Entity Information [Abstract]
Entity Registrant Name	CENTERPOINT ENERGY RESOURCES CORP
Entity Central Index Key	0001042773
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$ 0
Entity Common Stock, Shares Outstanding		1,000
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2012

CONDENSED STATEMENTS OF CONSOLIDATED INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Income Statement [Abstract]
Revenues	$ 846	$ 1,228	$ 2,396	$ 3,323
Expenses:
Natural gas	409	778	1,378	2,254
Operation and maintenance	228	237	467	477
Depreciation and amortization	70	65	139	131
Taxes other than income taxes	33	34	77	87
Total	740	1,114	2,061	2,949
Operating Income	106	114	335	374
Other Income (Expense):
Interest and other finance charges	(44)	(45)	(89)	(94)
Equity in earnings of unconsolidated affiliates	8	8	17	14
Other, net	0	1	0	2
Total	(36)	(36)	(72)	(78)
Income Before Income Taxes	70	78	263	296
Income tax expense	28	31	103	116
Net Income	$ 42	$ 47	$ 160	$ 180

CONDENSED STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Statement of Income and Comprehensive Income [Abstract]
Net Income	$ 42	$ 47	$ 160	$ 180
Other comprehensive income, net of tax:
Adjustment to pension and other postretirement plans (net of tax)	0	0	0	0
Other comprehensive income	0	0	0	0
Comprehensive income	$ 42	$ 47	$ 160	$ 180

- 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

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-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
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+ Details

- Definition

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

+ References

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+ Details

- Definition

This element represents Other Comprehensive Income or Loss, Net of Tax, for the period attributable to the parent entity. Includes deferred gains or losses on qualifying hedges, unrealized holding gains or losses on available-for-sale securities, minimum pension liability, and cumulative translation adjustment.

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+ Details

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Jun. 30, 2012	Dec. 31, 2011
Current Assets:
Cash and cash equivalents	$ 2	$ 1
Accounts receivable, net	354	542
Accrued unbilled revenue	66	253
Accounts and notes receivable - affiliated companies	9	17
Materials and supplies	88	86
Inventory	93	187
Non-trading derivative assets	67	87
Taxes receivable	2	1
Deferred income tax assets	7	8
Prepaid expenses and other current assets	166	122
Total current assets	854	1,304
Property, Plant and Equipment:
Property, plant and equipment	8,831	8,519
Less accumulated depreciation and amortization	1,596	1,489
Property, plant and equipment, net	7,235	7,030
Other Assets:
Goodwill	1,696	1,696
Non-trading derivative assets	22	20
Investment in unconsolidated affiliates	476	472
Other	184	165
Total other assets	2,378	2,353
Total Assets	10,467	10,687
Current Liabilities:
Short-term borrowings	30	62
Current portion of long-term debt	365	0
Accounts payable	227	427
Accounts and notes payable - affiliated companies	447	419
Taxes accrued	80	82
Interest accrued	48	48
Customer deposits	76	74
Non-trading derivative liabilities	27	46
Other	128	157
Total current liabilities	1,428	1,315
Other Liabilities:
Accumulated deferred income taxes, net	1,548	1,420
Non-trading derivative liabilities	14	6
Benefit obligations	108	108
Regulatory liabilities	618	597
Other	227	232
Total other liabilities	2,515	2,363
Long-term Debt	2,272	2,919
Commitments and Contingencies (Note 9)
Stockholder’s Equity:
Common stock	0	0
Paid-in capital	2,418	2,416
Retained earnings	1,841	1,681
Accumulated other comprehensive loss	(7)	(7)
Total stockholder’s equity	4,252	4,090
Total Liabilities and Stockholder's Equity	$ 10,467	$ 10,687

CONDENSED STATEMENTS OF CONSOLIDATED CASH FLOWS (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash Flows from Operating Activities:
Net Income	$ 160	$ 180
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	139	131
Amortization of deferred financing costs	7	6
Deferred income taxes	95	75
Write-down of natural gas inventory	4	0
Equity in earnings of unconsolidated affiliates, net of distributions	0	1
Changes in other assets and liabilities:
Accounts receivable and unbilled revenues, net.	367	305
Accounts receivable/payable, affiliates	5	(6)
Inventory	88	68
Taxes receivable	(1)	61
Accounts payable	(197)	(213)
Fuel cost recovery	(63)	(19)
Interest and taxes accrued	(4)	(2)
Non-trading derivatives, net	8	0
Margin deposits, net.	36	48
Other current assets	(18)	19
Other current liabilities	(17)	(28)
Other assets	0	4
Other liabilities	6	7
Other, net	2	1
Net cash provided by operating activities	617	638
Cash Flows from Investing Activities:
Capital expenditures, net of acquisitions	(232)	(318)
Acquisitions	(89)	0
Investment in unconsolidated affiliates	(4)	(7)
Other, net	(9)	1
Net cash used in investing activities	(334)	(324)
Cash Flows from Financing Activities:
Decrease in short-term borrowings, net	(32)	(14)
Payments of commercial paper, net	(285)	(113)
Proceeds from long-term debt	0	550
Payments of long-term debt	0	(606)
Cash paid for debt exchange	0	(58)
Debt issuance costs	0	(9)
Increase (decrease) in notes payable to affiliates	31	(60)
Other, net	4	0
Net cash used in financing activities	(282)	(310)
Net Increase in Cash and Cash Equivalents	1	4
Cash and Cash Equivalents at Beginning of Period	1	1
Cash and Cash Equivalents at End of Period	2	5
Cash Payments:
Interest, net of capitalized interest	82	90
Income taxes (refunds), net	1	(19)
Non-cash transactions:
Accounts payable related to capital expenditures	$ 50	$ 47

Background	6 Months Ended
Background	Jun. 30, 2012
Background and Basis of Presentation [Abstract]
Background and Basis of Presentation	Background and Basis of Presentation General. Included in this Quarterly Report on Form 10-Q (Form 10-Q) of CenterPoint Energy Resources Corp. (CERC Corp.) are the condensed consolidated interim financial statements and notes (Interim Condensed Financial Statements) of CenterPoint Energy Resources Corp. and its subsidiaries (collectively, CERC). 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 CERC Corp. for the year ended December 31, 2011. Background. CERC 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. CERC Corp. is an indirect wholly owned subsidiary of CenterPoint Energy, Inc. (CenterPoint Energy), a public utility holding company. 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. CERC’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 CERC’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 CERC’s reportable business segments, see Note 11.

- Definition

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

+ References

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+ Details

New Accounting Pronouncements	6 Months Ended
New Accounting Pronouncements	Jun. 30, 2012
New Accounting Pronouncements [Abstract]
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	New Accounting Pronouncements Management believes the impact of recently issued standards, which are not yet effective, will not have a material impact on CERC’s consolidated financial position, results of operations or cash flows upon adoption.

Employee Benefit Plans Employee Benefit Plans (Notes)

6 Months Ended

Jun. 30, 2012

Employee Benefit Plans [Abstract]

Pension and Other Postretirement Benefits Disclosure [Text Block]

Employee Benefit Plans

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



	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2011		2012		2011		2012
	(in millions)
Interest cost on accumulated benefit obligation	2		2		3		3
Amortization of prior service cost	—		—		1		1
Amortization of loss	—		1		—		1
Net periodic cost	$	2	$	3	$	4	$	5

CERC expects to contribute approximately $9 million to its postretirement benefit plan in 2012, of which $4 million has been contributed as of June 30, 2012.

- Definition

The entire disclosure for pension and other postretirement benefits.

+ References

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+ Details

Derivative Instruments

6 Months Ended

Jun. 30, 2012

Derivative Instruments [Abstract]

Derivative Instruments

CERC is exposed to various market risks. These risks arise from transactions entered into in the normal course of business. CERC 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 CERC’s Consolidated Balance Sheets at their fair value unless CERC elects the normal purchase and sales exemption for qualified physical transactions. A derivative may be designated as a normal purchase or normal sale if the intent is to physically receive or deliver the product for use or sale in the normal course of business.

CenterPoint Energy has a Risk Oversight Committee composed of corporate and business segment officers that oversees all commodity price, weather and credit risk activities, including CERC’s marketing, risk management services and hedging activities. The committee’s duties are to establish CERC’s commodity risk policies, allocate board-approved commercial risk limits, approve use of new products and commodities, monitor positions and ensure compliance with CERC’s risk management policies and procedures and limits established by CenterPoint Energy’s board of directors.

CERC’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. CERC 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.

During the three months ended June 30, 2011, CERC recorded decreased natural gas revenues from unrealized net losses of $2 million and decreased natural gas expense from unrealized net gains of $6 million, resulting in a net unrealized gain of $4 million. During the three months ended June 30, 2012, CERC recorded decreased natural gas revenues from unrealized net losses of $41 million and decreased natural gas expense from unrealized net gains of $37 million, resulting in a net unrealized loss of $4 million. During the six months ended June 30, 2011, CERC recorded decreased natural gas revenues from unrealized net losses of $19 million and decreased natural gas expense from unrealized net gains of $21 million, resulting in a net unrealized gain of $2 million. During the six months ended June 30, 2012, CERC recorded decreased natural gas revenues from unrealized net losses of $46 million and decreased natural gas expense from unrealized net gains of $41 million, resulting in a net unrealized loss of $5 million.

Weather Hedges. CERC has weather normalization or other rate mechanisms that mitigate the impact of weather on its gas operations in Arkansas, Louisiana, Mississippi, Oklahoma and a portion of Texas. The remaining Gas Operations jurisdictions 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 the remaining jurisdictions. CERC enters into heating-degree day swaps for these 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 have limits and are based on ten-year normal weather. During the three and six months ended June 30, 2011, CERC recognized losses of $1 million and $6 million, respectively, related to these swaps. During the three and six months ended June 30, 2012, CERC recognized gains of $-0- and $6 million, 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 CERC’s derivative instruments and hedging activities. The first two tables provide a balance sheet overview of CERC’s Derivative Assets and Liabilities as of December 31, 2011 and June 30, 2012, while the last table provides a breakdown of the related income statement impacts for the three and six months ended June 30, 2011 and 2012.



Fair Value of Derivative Instruments
		December 31, 2011
Total derivatives not designated as hedging instruments	Balance Sheet Location	Derivative Assets Fair Value (2) (3)		Derivative Liabilities Fair Value (2) (3)
		(in millions)
Natural gas derivatives (1)	Current Assets	$	88	$	1
Natural gas derivatives (1)	Other Assets	20		—
Natural gas derivatives (1)	Current Liabilities	15		110
Natural gas derivatives (1)	Other Liabilities	—		13
Total		$	123	$	124

________________


(1)	Natural gas contracts are subject to master netting arrangements and are presented on a net basis in the Condensed Consolidated Balance Sheets. This netting causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets.


(2)	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 633 billion cubic feet (Bcf) or a net 84 Bcf long position. Of the net long position, basis swaps constitute 74 Bcf and volumes associated with price stabilization activities of the Natural Gas Distribution business segment constitute 6 Bcf.


(3)	The net of total non-trading derivative assets and liabilities is a $55 million asset as shown on CERC’s Condensed Consolidated Balance Sheets, and is comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $56 million.



Fair Value of Derivative Instruments
		June 30, 2012
Total derivatives not designated as hedging instruments	Balance Sheet Location	Derivative Assets Fair Value (2) (3)		Derivative Liabilities Fair Value (2) (3)
		(in millions)
Natural gas derivatives (1)	Current Assets	$	68	$	1
Natural gas derivatives (1)	Other Assets	22		—
Natural gas derivatives (1)	Current Liabilities	12		56
Natural gas derivatives (1)	Other Liabilities	1		18
Total		$	103	$	75

________________


(1)	Natural gas contracts are subject to master netting arrangements and are presented on a net basis in the Condensed Consolidated Balance Sheets. This netting causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets.


(2)	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 785 Bcf or a net 114 Bcf long position. Of the net long position, basis swaps constitute 71 Bcf.


(3)	The net of total non-trading derivative assets and liabilities is a $48 million asset as shown on CERC’s Condensed Consolidated Balance Sheets, and is comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $20 million.

For CERC’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.



Income Statement Impact of Derivative Activity
		Three Months Ended June 30,
Total derivatives not designated as hedging instruments	Income Statement Location	2011			2012
		(in millions)
Natural gas derivatives	Gains (Losses) in Revenue	$	9		$	(8	)
Natural gas derivatives (1)	Gains (Losses) in Expense: Natural Gas	(12		)	13
Total		$	(3	)	$	5

________________

(1)

The Gains (Losses) in Expense: Natural Gas includes $(17) million of costs in 2011 associated with price stabilization activities of the Natural Gas Distribution business segment that will be ultimately recovered through purchased gas adjustments. There are no such costs associated with price stabilization activities of the Natural Gas Distribution business segment in the three months ended June 30, 2012.



Income Statement Impact of Derivative Activity
		Six Months Ended June 30,
Total derivatives not designated as hedging instruments	Income Statement Location	2011			2012
		(in millions)
Natural gas derivatives	Gains (Losses) in Revenue	$	14		$	43
Natural gas derivatives (1)	Gains (Losses) in Expense: Natural Gas	(49		)	(68		)
Total		$	(35	)	$	(25	)

________________


(1)	The Gains (Losses) in Expense: Natural Gas includes $(62) million and $(38) million of costs in 2011 and 2012, respectively, associated with price stabilization activities of the Natural Gas Distribution business segment that will be ultimately recovered through purchased gas adjustments.

CERC enters into financial derivative contracts containing material adverse change provisions. These provisions could require CERC to post additional collateral if the Standard & Poor’s Ratings Services or Moody’s Investors Service, Inc. credit ratings of CERC 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, 2011 and June 30, 2012 was $39 million and $11 million, respectively. The aggregate fair value of assets that were posted as collateral was less than $1 million at both December 31, 2011 and June 30, 2012. If all derivative contracts (in a net liability position) containing credit risk contingent features were triggered at December 31, 2011 and June 30, 2012, $38 million and $10 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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 45
-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 2: 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 3: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Fair Value Measurements

6 Months Ended

Jun. 30, 2012

Fair Value Measurements [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 CERC’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 CERC’s judgments about the assumptions market participants would use in pricing the asset or liability since limited market data exists. CERC develops these inputs based on the best information available, including CERC’s own data. A market approach is utilized to value CERC’s Level 3 assets or liabilities. Currently, CERC’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 $2.52-$4.64 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 0-90%) as an unobservable input. CERC’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, CERC’s long forwards lose value whereas its short forwards gain in value. If volatility decreases, CERC’s long options lose value whereas its short options gain in value.

CERC 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. CERC 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 CERC’s assets and liabilities (including derivatives that are presented net) measured at fair value on a recurring basis as of December 31, 2011 and June 30, 2012, and indicate the fair value hierarchy of the valuation techniques utilized by CERC 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, 2011
	(in millions)
Assets
Corporate equities	$	1	$	—	$	—	$	—		$	1
Investments, including money market funds (2)	11		—		—		—			11
Natural gas derivatives	1		112		10		(16		)	107
Total assets	$	13	$	112	$	10	$	(16	)	$	119
Liabilities
Natural gas derivatives	$	19	$	101	$	4	$	(72	)	$	52
Total liabilities	$	19	$	101	$	4	$	(72	)	$	52

________________


(1)	Amounts represent the impact of legally enforceable master netting agreements that allow CERC to settle positive and negative positions and also include cash collateral of $56 million posted with the same counterparties.


(2)	Excludes money market fund investments included in Cash and cash equivalents.



	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 June 30, 2012
	(in millions)
Assets
Corporate equities	$	1	$	—	$	—	$	—		$	1
Investments, including money market funds (2)	11		—		—		—			11
Natural gas derivatives	3		71		29		(14		)	89
Total assets	$	15	$	71	$	29	$	(14	)	$	101
Liabilities
Natural gas derivatives	$	11	$	38	$	26	$	(34	)	$	41
Total liabilities	$	11	$	38	$	26	$	(34	)	$	41

________________


(1)	Amounts represent the impact of legally enforceable master netting agreements that allow CERC to settle positive and negative positions and also include cash collateral of $20 million posted with the same counterparties.


(2)	Excludes money market fund investments included in Cash and cash equivalents.

The following tables present additional information about assets or liabilities, including derivatives that are measured at fair value on a recurring basis for which CERC 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 June 30,
	2011			2012
	(in millions)
Beginning balance	$	6		$	3
Total unrealized gains ⁽¹⁾	1			2
Total settlements ⁽¹⁾	(2		)	(2		)
Transfers out of Level 3	—			—
Ending balance ⁽²⁾	$	5		$	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	$	1		$	1



	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Derivative Assets and Liabilities, net
	Six Months Ended June 30,
	2011			2012
	(in millions)
Beginning balance	$	3		$	6
Total unrealized gains ⁽¹⁾	4			4
Total settlements ⁽¹⁾	(2		)	(6		)
Transfers out of Level 3	—			(1		)
Ending balance ⁽²⁾	$	5		$	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	$	3		$	2

_____________


(1)	CERC did not have Level 3 unrealized gain (losses) or settlements related to price stabilization activities of the Natural Gas Distribution business segment for either the three or six months ended June 30, 2011 or 2012.


(2)	During both the three and six months ended June 30, 2011 and 2012, CERC did not have Level 3 purchases, sales or significant transfers into Level 3.

Estimated Fair Value of Financial Instruments

The fair values of cash and cash equivalents and short-term borrowings are estimated to be approximately equivalent to carrying amounts and have been excluded from the table below. Non-trading derivative assets and liabilities 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, 2011				June 30, 2012
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(in millions)
Financial liabilities:
Long-term debt	$	2,919	$	3,272	$	2,637	$	2,981

- 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 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 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
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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 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-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 4: 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 5: 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.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32, 33, 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.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 17-22, 27, 28
-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 Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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-Name Accounting Standards Codification
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Reference 14: http://www.xbrl.org/2003/role/presentationRef
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-Topic 820
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-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19296-110258

+ Details

Goodwill

6 Months Ended

Jun. 30, 2012

Goodwill [Abstract]

Goodwill and Intangible Assets Disclosure [Text Block]

Goodwill

Goodwill by reportable business segment as of both December 31, 2011 and June 30, 2012 is as follows (in millions):



Natural Gas Distribution	$	746
Interstate Pipelines	579
Competitive Natural Gas Sales and Services	335
Field Services	25
Other Operations	11
Total	$	1,696

- 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

Related Party Transactions	6 Months Ended
Related Party Transactions	Jun. 30, 2012
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions CERC participates in a “money pool” through which it can borrow or invest on a short-term basis. Funding needs are aggregated and external borrowing or investing is based on the net cash position. The net funding requirements of the money pool are expected to be met with borrowings under CenterPoint Energy’s revolving credit facility or the sale of CenterPoint Energy’s commercial paper. CERC had money pool borrowings of $383 million and $414 million at December 31, 2011 and June 30, 2012, respectively, which are included in accounts and notes payable —affiliated companies in the Condensed Consolidated Balance Sheets. CERC had net interest expense related to affiliate borrowings of less than $1 million for both the three and six months ended June 30, 2011, and $1 million and $2 million, respectively, for the three and six months ended June 30, 2012. CenterPoint Energy provides some corporate services to CERC. The costs of services have been charged directly to CERC using methods that management believes are reasonable. These methods include negotiated usage rates, dedicated asset assignment and proportionate corporate formulas based on operating expenses, assets, gross margin, employees and a composite of assets, gross margin and employees. These charges are not necessarily indicative of what would have been incurred had CERC not been an affiliate of CenterPoint Energy. Amounts charged to CERC for these services were $42 million and $41 million for the three months ended June 30, 2011 and 2012, respectively, and $81 million for both the six months ended June 30, 2011 and 2012, and are included primarily in operation and maintenance expenses.

- Definition

The entire disclosure for related party transactions, including the nature of the relationship(s), a description of the transactions, the amount of the transactions, the effects of any change in the method of establishing the terms of the transaction from the previous period, stated interest rate, expiration date, terms and manner of settlement per the agreement with the related party, and amounts due to or from related parties. If the entity and one or more other entities are under common ownership or management control and this control affects the operating results or financial position, disclosure includes the nature of the control relationship even if there are no transactions between the entities. Disclosure may also include the aggregate amount of current and deferred tax expense for each statement of earnings presented where the entity is a member of a group that files a consolidated tax return, the amount of any tax related balances due to or from affiliates as of the date of each statement of financial position presented, the principal provisions of the method by which the consolidated amount of current and deferred tax expense is allocated to the members of the group and the nature and effect of any changes in that method. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 4
-Section 08
-Paragraph k

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 3A
-Section 04
-Paragraph b

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 57
-Paragraph 1-4
-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 Accounting Standards Codification
-Topic 850
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-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

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Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

Reference 7: 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.(k))
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39691-107864

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39678-107864

+ Details

Short-term Borrowings and Long-term Debt

6 Months Ended

Jun. 30, 2012

Short-term Borrowings and Long-term Debt [Abstract]

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 March 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 they had an associated principal obligation of $62 million and $30 million as of December 31, 2011 and June 30, 2012, respectively.


(b)	Long-term Debt

Revolving Credit Facility. As of December 31, 2011 and June 30, 2012, CERC had the following revolving credit facility and utilization of such facility (in millions):



		December 31, 2011						June 30, 2012
Size of Facility		Loans		Letters of Credit		Commercial Paper		Loans		Letters of Credit		Commercial Paper
$	950	$	—	$	—	$	285	$	—	$	—	$	—

CERC Corp.’s $950 million credit facility, which is scheduled to terminate September 9, 2016, can be drawn at the London Interbank Offered Rate 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 its 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

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2012
Commitments and Contingencies [Abstract]
Commitments and Contingencies	Commitments and Contingencies (a) Natural Gas Supply Commitments Natural gas supply commitments include natural gas contracts related to CERC’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 CERC’s Condensed Consolidated Balance Sheets as of December 31, 2011 and June 30, 2012 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 June 30, 2012, minimum payment obligations for natural gas supply commitments are approximately $185 million for the remaining six months in 2012, $428 million in 2013, $339 million in 2014, $210 million in 2015, $148 million in 2016 and $251 million after 2016. (b) Long-Term Gas Gathering and Treating Agreements CenterPoint Energy Field Services, LLC (CEFS), a subsidiary of CERC Corp., 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. (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 are 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 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. 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). Neither the sale of the retail business nor the merger with Mirant Corporation 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 have been 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 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 the other defendants in the case, each of whom had demonstrated Federal Energy Regulatory Commission jurisdictional sales for resale during the relevant period, based on federal preemption. The plaintiffs have appealed this ruling to the United States Court of Appeals for the Ninth Circuit. 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. 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 British thermal unit (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. In July 2012, the plaintiffs filed a motion to dismiss certain defendants from both lawsuits, including the remaining CenterPoint Energy defendants. CERC believes that there has been no systematic mismeasurement of gas and that these lawsuits are without merit. CERC does not expect the ultimate outcome of the lawsuits to have a material impact on its financial condition, results of operations or cash flows. 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 June 30, 2012, CERC had accrued $13 million for remediation of these Minnesota sites and the estimated range of possible remediation costs for these sites 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 June 30, 2012, CERC had collected $5.7 million from insurance companies to be used to mitigate future environmental costs. 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 does not expect the ultimate outcome of these investigations will have a material adverse impact on its financial condition, results of operations or cash flows. Asbestos. Some facilities owned by CERC’s predecessors contain or have contained asbestos insulation and other asbestos-containing materials. CERC or its predecessor companies 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 CERC, but most existing claims relate to facilities previously owned by CERC’s subsidiaries. CERC anticipates that additional claims like those received may be asserted in the future. Although their ultimate outcome cannot be predicted at this time, CERC intends to continue vigorously contesting claims that it does not consider to have merit and does not expect, based on its experience to date, these matters, either individually or in the aggregate, to have a material adverse effect on its financial condition, results of operations or cash flows. Other Environmental. From time to time CERC identifies the presence of environmental contaminants on property where it conducts or has conducted operations. Other such sites involving contaminants may be identified in the future. CERC has and expects to continue to remediate identified sites consistent with its legal obligations. From time to time CERC 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, CERC 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, CERC does not expect, based on its experience to date, these matters, either individually or in the aggregate, to have a material adverse effect on its financial condition, results of operations or cash flows. Other Proceedings CERC 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. CERC regularly analyzes current information and, as necessary, provides accruals for probable liabilities on the eventual disposition of these matters. CERC does not expect the disposition of these matters to have a material adverse effect on its financial condition, results of operations or cash flows. (f) 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 $82 million as of June 30, 2012. Market conditions in the fourth quarters of 2010 and 2011 required posting of security under the agreement, and GenOn has posted approximately $28 million of collateral as of June 30, 2012. If GenOn should fail to perform the contractual obligations, CERC could have to honor its guarantee and, in such event, collateral provided as security may be insufficient to satisfy CERC’s obligations.

- Definition

The entire disclosure for commitments and contingencies.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 14
-Paragraph 3
-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 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9, 10, 11, 12
-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 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.25)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25287-109308

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-Publisher FASB
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-Topic 825
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6449706&loc=d3e16207-108621

+ Details

Income Taxes

6 Months Ended

Jun. 30, 2012

Income Taxes [Abstract]

Income Taxes

During the three and six months ended June 30, 2012, the effective tax rate was 40% and 39%, respectively. The effective tax rate for 2012 was consistent with the same periods in 2011.

The following table summarizes CERC’s unrecognized tax benefits at December 31, 2011 and June 30, 2012.



	December 31, 2011			June 30, 2012
	(in millions)
Unrecognized tax benefits (expense)	$	8		$	(11	)
Portion of unrecognized tax benefits that, if recognized, would reduce the effective income tax rate	6			6
Interest accrued on unrecognized tax benefits	(4		)	(7		)

CERC does not expect the amount of unrecognized tax benefits to change materially over the 12 months ending June 30, 2013.

CenterPoint Energy has a tentative settlement with the Internal Revenue Service (IRS) for tax years 2008 and 2009 that is under review by the Joint Committee on Taxation. In May 2012, the IRS commenced its examination of CenterPoint Energy’s 2010 consolidated income tax return.

- 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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph h
-Article 4

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 136, 172
-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 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43, 44, 45, 46, 47, 48, 49
-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 Accounting Standards Codification
-Topic 740
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h))
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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

+ Details

Reportable Business Segments

6 Months Ended

Jun. 30, 2012

Reportable Business Segments [Abstract]

Reportable Business Segments

Because CERC is an indirect wholly owned subsidiary of CenterPoint Energy, CERC’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. CERC uses operating income as the measure of profit or loss for its business segments.

CERC’s reportable business segments include the following: Natural Gas Distribution, Competitive Natural Gas Sales and Services, Interstate Pipelines, Field Services and Other Operations. 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 CERC’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. The Other Operations business segment includes unallocated corporate costs and inter-segment eliminations.

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



	For the Three Months Ended June 30, 2011
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)
Natural Gas Distribution	$	448	$	4		$	13
Competitive Natural Gas Sales and Services	581		5			3
Interstate Pipelines	111		31			60
Field Services	88		10			39
Other	—		—			(1		)
Reconciling Eliminations	—		(50		)	—
Consolidated	$	1,228	$	—		$	114

	For the Three Months Ended June 30, 2012
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)
Natural Gas Distribution	$	360	$	6		$	9
Competitive Natural Gas Sales and Services	302		6			(4		)
Interstate Pipelines	88		37			52
Field Services	96		8			51
Other	—		—			(2		)
Reconciling Eliminations	—		(57		)	—
Consolidated	$	846	$	—		$	106

	For the Six Months Ended June 30, 2011
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)			Total Assets as of December 31, 2011
Natural Gas Distribution	$	1,655	$	9		$	155		$	4,636
Competitive Natural Gas Sales and Services	1,278		14			13			1,089
Interstate Pipelines	224		65			136			3,867
Field Services	166		22			75			1,894
Other	—		—			(5		)	660
Reconciling Eliminations	—		(110		)	—			(1,459		)
Consolidated	$	3,323	$	—		$	374		$	10,687

	For the Six Months Ended June 30, 2012
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)			Total Assets as of June 30, 2012
Natural Gas Distribution	$	1,209	$	11		$	130		$	4,503
Competitive Natural Gas Sales and Services	822		11			(3		)	1,023
Interstate Pipelines	170		82			112			3,935
Field Services	195		14			98			1,976
Other	—		—			(2		)	363
Reconciling Eliminations	—		(118		)	—			(1,333		)
Consolidated	$	2,396	$	—		$	335		$	10,467

- 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 131
-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 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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+ Details

Other Current Assets and Liabilities	6 Months Ended
Other Current Assets and Liabilities	Jun. 30, 2012
Other Current Assets and Liabilities [Abstract]
Other Current Assets and Liabilities [Text Block]	Other Current Assets and Liabilities Included in other current assets on the Condensed Consolidated Balance Sheets at both December 31, 2011 and June 30, 2012 were $17 million of margin deposits and $63 million and $102 million of under-recovered gas cost at December 31, 2011 and June 30, 2012, respectively. Included in other current liabilities on the Condensed Consolidated Balance Sheets at December 31, 2011 and June 30, 2012 were $14 million and $11 million, respectively, of over-recovered gas cost.

Subsequent Events	6 Months Ended
Subsequent Events	Jun. 30, 2012
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events As of June 30, 2012, CERC owned a 50% interest in Waskom Gas Processing Company (Waskom), a Texas general partnership, which owns and operates a natural gas processing plant and natural gas gathering assets. This investment is accounted for under the equity method as CERC exercises significant influence over Waskom. On July 31, 2012, CERC purchased the remaining 50% interest in Waskom as well as other gathering assets from a third-party for approximately $275 million. The amount of the purchase price allocated to the acquisition of the remaining 50% interest in Waskom was approximately $200 million, with the remaining purchase price allocated to the other gathering assets, based on a discounted cash flow methodology. The purchase of the remaining 50% interest in Waskom was determined to be a business combination achieved in stages, and as such CERC recorded a pre-tax gain of approximately $130 million on July 31, 2012, which is the result of remeasuring CERC's original 50% interest in Waskom to fair value.

Employee Benefit Plans

6 Months Ended

Jun. 30, 2012

Employee Benefit Plans [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

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



	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2011		2012		2011		2012
	(in millions)
Interest cost on accumulated benefit obligation	2		2		3		3
Amortization of prior service cost	—		—		1		1
Amortization of loss	—		1		—		1
Net periodic cost	$	2	$	3	$	4	$	5

Derivative Instruments Derivative Instruments (Tables)

6 Months Ended

Jun. 30, 2012

Derivative Instruments [Abstract]

Fair Value of Derivative Instruments Table



Fair Value of Derivative Instruments
		December 31, 2011
Total derivatives not designated as hedging instruments	Balance Sheet Location	Derivative Assets Fair Value (2) (3)		Derivative Liabilities Fair Value (2) (3)
		(in millions)
Natural gas derivatives (1)	Current Assets	$	88	$	1
Natural gas derivatives (1)	Other Assets	20		—
Natural gas derivatives (1)	Current Liabilities	15		110
Natural gas derivatives (1)	Other Liabilities	—		13
Total		$	123	$	124

________________


(1)	Natural gas contracts are subject to master netting arrangements and are presented on a net basis in the Condensed Consolidated Balance Sheets. This netting causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets.


(2)	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 633 billion cubic feet (Bcf) or a net 84 Bcf long position. Of the net long position, basis swaps constitute 74 Bcf and volumes associated with price stabilization activities of the Natural Gas Distribution business segment constitute 6 Bcf.


(3)	The net of total non-trading derivative assets and liabilities is a $55 million asset as shown on CERC’s Condensed Consolidated Balance Sheets, and is comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $56 million.



Fair Value of Derivative Instruments
		June 30, 2012
Total derivatives not designated as hedging instruments	Balance Sheet Location	Derivative Assets Fair Value (2) (3)		Derivative Liabilities Fair Value (2) (3)
		(in millions)
Natural gas derivatives (1)	Current Assets	$	68	$	1
Natural gas derivatives (1)	Other Assets	22		—
Natural gas derivatives (1)	Current Liabilities	12		56
Natural gas derivatives (1)	Other Liabilities	1		18
Total		$	103	$	75

________________


(1)	Natural gas contracts are subject to master netting arrangements and are presented on a net basis in the Condensed Consolidated Balance Sheets. This netting causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets.


(2)	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 785 Bcf or a net 114 Bcf long position. Of the net long position, basis swaps constitute 71 Bcf.


(3)	The net of total non-trading derivative assets and liabilities is a $48 million asset as shown on CERC’s Condensed Consolidated Balance Sheets, and is comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $20 million.

Income Statement Impact of Derivative Activity Table



Income Statement Impact of Derivative Activity
		Three Months Ended June 30,
Total derivatives not designated as hedging instruments	Income Statement Location	2011			2012
		(in millions)
Natural gas derivatives	Gains (Losses) in Revenue	$	9		$	(8	)
Natural gas derivatives (1)	Gains (Losses) in Expense: Natural Gas	(12		)	13
Total		$	(3	)	$	5

________________

(1)



Income Statement Impact of Derivative Activity
		Six Months Ended June 30,
Total derivatives not designated as hedging instruments	Income Statement Location	2011			2012
		(in millions)
Natural gas derivatives	Gains (Losses) in Revenue	$	14		$	43
Natural gas derivatives (1)	Gains (Losses) in Expense: Natural Gas	(49		)	(68		)
Total		$	(35	)	$	(25	)

________________


(1)	The Gains (Losses) in Expense: Natural Gas includes $(62) million and $(38) million of costs in 2011 and 2012, 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)

6 Months Ended

Jun. 30, 2012

Fair Value Measurements [Abstract]

Fair Value, Assets Measured on Recurring Basis [Table Text Block]



	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, 2011
	(in millions)
Assets
Corporate equities	$	1	$	—	$	—	$	—		$	1
Investments, including money market funds (2)	11		—		—		—			11
Natural gas derivatives	1		112		10		(16		)	107
Total assets	$	13	$	112	$	10	$	(16	)	$	119
Liabilities
Natural gas derivatives	$	19	$	101	$	4	$	(72	)	$	52
Total liabilities	$	19	$	101	$	4	$	(72	)	$	52

________________


(1)	Amounts represent the impact of legally enforceable master netting agreements that allow CERC to settle positive and negative positions and also include cash collateral of $56 million posted with the same counterparties.


(2)	Excludes money market fund investments included in Cash and cash equivalents.



	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 June 30, 2012
	(in millions)
Assets
Corporate equities	$	1	$	—	$	—	$	—		$	1
Investments, including money market funds (2)	11		—		—		—			11
Natural gas derivatives	3		71		29		(14		)	89
Total assets	$	15	$	71	$	29	$	(14	)	$	101
Liabilities
Natural gas derivatives	$	11	$	38	$	26	$	(34	)	$	41
Total liabilities	$	11	$	38	$	26	$	(34	)	$	41

________________


(1)	Amounts represent the impact of legally enforceable master netting agreements that allow CERC to settle positive and negative positions and also include cash collateral of $20 million posted with the same counterparties.


(2)	Excludes money market fund investments included in Cash and cash equivalents.

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]



	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Derivative Assets and Liabilities, net
	Three Months Ended June 30,
	2011			2012
	(in millions)
Beginning balance	$	6		$	3
Total unrealized gains ⁽¹⁾	1			2
Total settlements ⁽¹⁾	(2		)	(2		)
Transfers out of Level 3	—			—
Ending balance ⁽²⁾	$	5		$	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	$	1		$	1



	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Derivative Assets and Liabilities, net
	Six Months Ended June 30,
	2011			2012
	(in millions)
Beginning balance	$	3		$	6
Total unrealized gains ⁽¹⁾	4			4
Total settlements ⁽¹⁾	(2		)	(6		)
Transfers out of Level 3	—			(1		)
Ending balance ⁽²⁾	$	5		$	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	$	3		$	2

_____________


(1)	CERC did not have Level 3 unrealized gain (losses) or settlements related to price stabilization activities of the Natural Gas Distribution business segment for either the three or six months ended June 30, 2011 or 2012.


(2)	During both the three and six months ended June 30, 2011 and 2012, CERC did not have Level 3 purchases, sales or significant transfers into Level 3.

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



	December 31, 2011				June 30, 2012
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(in millions)
Financial liabilities:
Long-term debt	$	2,919	$	3,272	$	2,637	$	2,981

- 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, 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, issuances, 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 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.

Reference 2: 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 3: 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 4: 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 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-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 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-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 7: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Goodwill Goodwill (Tables)

6 Months Ended

Jun. 30, 2012

Goodwill [Abstract]

Schedule of Goodwill [Table Text Block]

Goodwill by reportable business segment as of both December 31, 2011 and June 30, 2012 is as follows (in millions):



Natural Gas Distribution	$	746
Interstate Pipelines	579
Competitive Natural Gas Sales and Services	335
Field Services	25
Other Operations	11
Total	$	1,696

- Definition

Tabular disclosure of goodwill by reportable segment and in total. Disclosure details may include, but are not limited to, the carrying amount of goodwill, goodwill acquired during the year, goodwill impairment losses recognized, goodwill written-off due to the sale of a business unit, goodwill not yet allocated, and any other changes to goodwill.

+ References + Details

Short-term Borrowings and Long-term Debt (Tables)

6 Months Ended

Jun. 30, 2012

Short-term Borrowings and Long-term Debt [Abstract]

Schedule of Line of Credit Facilities [Table Text Block]

Revolving Credit Facility. As of December 31, 2011 and June 30, 2012, CERC had the following revolving credit facility and utilization of such facility (in millions):



		December 31, 2011						June 30, 2012
Size of Facility		Loans		Letters of Credit		Commercial Paper		Loans		Letters of Credit		Commercial Paper
$	950	$	—	$	—	$	285	$	—	$	—	$	—

Income Taxes (Tables)

6 Months Ended

Jun. 30, 2012

Income Taxes [Abstract]

Summary of Unrecognized Tax Benefits [Table Text Block]

The following table summarizes CERC’s unrecognized tax benefits at December 31, 2011 and June 30, 2012.



	December 31, 2011			June 30, 2012
	(in millions)
Unrecognized tax benefits (expense)	$	8		$	(11	)
Portion of unrecognized tax benefits that, if recognized, would reduce the effective income tax rate	6			6
Interest accrued on unrecognized tax benefits	(4		)	(7		)

Reportable Business Segments (Tables)

6 Months Ended

Jun. 30, 2012

Reportable Business Segments [Abstract]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

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



	For the Three Months Ended June 30, 2011
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)
Natural Gas Distribution	$	448	$	4		$	13
Competitive Natural Gas Sales and Services	581		5			3
Interstate Pipelines	111		31			60
Field Services	88		10			39
Other	—		—			(1		)
Reconciling Eliminations	—		(50		)	—
Consolidated	$	1,228	$	—		$	114

	For the Three Months Ended June 30, 2012
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)
Natural Gas Distribution	$	360	$	6		$	9
Competitive Natural Gas Sales and Services	302		6			(4		)
Interstate Pipelines	88		37			52
Field Services	96		8			51
Other	—		—			(2		)
Reconciling Eliminations	—		(57		)	—
Consolidated	$	846	$	—		$	106

	For the Six Months Ended June 30, 2011
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)			Total Assets as of December 31, 2011
Natural Gas Distribution	$	1,655	$	9		$	155		$	4,636
Competitive Natural Gas Sales and Services	1,278		14			13			1,089
Interstate Pipelines	224		65			136			3,867
Field Services	166		22			75			1,894
Other	—		—			(5		)	660
Reconciling Eliminations	—		(110		)	—			(1,459		)
Consolidated	$	3,323	$	—		$	374		$	10,687

	For the Six Months Ended June 30, 2012
	Revenues from External Customers		Inter-segment Revenues			Operating Income (Loss)			Total Assets as of June 30, 2012
Natural Gas Distribution	$	1,209	$	11		$	130		$	4,503
Competitive Natural Gas Sales and Services	822		11			(3		)	1,023
Interstate Pipelines	170		82			112			3,935
Field Services	195		14			98			1,976
Other	—		—			(2		)	363
Reconciling Eliminations	—		(118		)	—			(1,333		)
Consolidated	$	2,396	$	—		$	335		$	10,467

- 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

Employee Benefit Plans Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Interest cost on accumulated benefit obligation	$ 2	$ 2	$ 3	$ 3
Amortization of prior service cost	0	0	1	1
Amortization of loss	1	0	1	0
Net periodic cost	3	$ 2	5	$ 4
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	$ 9		9
Defined Benefit Plan, Contributions by Employer			$ 4

- Definition

The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

+ References + Details

Derivative Instruments Derivative Instruments (Details)
$ in Millions

3 Months Ended

6 Months Ended

12 Months Ended

Jun. 30, 2012

USD ($)

Jun. 30, 2011

USD ($)

Jun. 30, 2012

USD ($)

bcf

Jun. 30, 2011

USD ($)

Dec. 31, 2011

USD ($)

bcf

Derivatives, Fair Value [Line Items]

Increased (decreased) natural gas revenues from the unrealized net gains (losses) of derivatives instrument

$ (41)

$ (2)

$ (46)

$ (19)

Increased (decreased) natural gas expense from the unrealized net (gains) losses of derivatives instrument

(37)

(6)

(41)

(21)

Net unrealized gain (loss) from derivatives instrument

(4)

(5)

Gains (losses) recognized from weather hedges

(6)

Derivative Assets Fair Value

103

^[1],[2]

103

^[1],[2]

$ 123

^[3],[4]

Derivative Liabilities Fair Value

^[1],[2]

$ 75

^[1],[2]

$ 124

^[3],[4]

Derivative gross volumes (Bcf)

785

633

Net long position (Bcf) | bcf

114

Derivative Gross Volume Basis Swaps Long Position | bcf

Derivative Gross Volume Segment Long Position | bcf

Total non-trading derivative assets and liabilities net of collateral

$ 48

$ 55

Collateral Netting

Derivative gains and (losses) in the Statements of Consolidated Income

(3)

(25)

(35)

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

The aggregate fair value of assets already posted as collateral

Credit Risk Contingent Feature assets

Natural Gas Derivatives [Member] | Other Liabilities [Member]

Derivatives, Fair Value [Line Items]

Derivative Assets Fair Value

^[5]

^[1],[2]

^[3],[4]

Derivative Liabilities Fair Value

^[5]

^[1],[2]

^[3],[4]

Natural Gas Derivatives [Member] | Current Liabilities [Member]

Derivatives, Fair Value [Line Items]

Derivative Assets Fair Value

^[5]

^[1],[2]

^[3],[4]

Derivative Liabilities Fair Value

^[5]

^[1],[2]

110

^[3],[4]

Natural Gas Derivatives [Member] | Other Assets [Member]

Derivatives, Fair Value [Line Items]

Derivative Assets Fair Value

^[5]

^[1],[2]

^[3],[4]

Derivative Liabilities Fair Value

^[5]

^[1],[2]

^[3],[4]

Natural Gas Derivatives [Member] | Current Assets [Member]

Derivatives, Fair Value [Line Items]

Derivative Assets Fair Value

^[5]

^[1],[2]

^[3],[4]

Derivative Liabilities Fair Value

^[5]

^[1],[2]

$ 1

^[3],[4]

Natural Gas Derivatives [Member] | Sales [Member]

Derivatives, Fair Value [Line Items]

Derivative gains and (losses) in the Statements of Consolidated Income

(8)

Natural Gas Derivatives [Member] | Cost of Sales [Member]

Derivatives, Fair Value [Line Items]

Derivative gains and (losses) in the Statements of Consolidated Income

$ 13

^[6]

(12)

^[6]

(68)

^[7]

(49)

^[7]

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

$ (17)

$ (38)

$ (62)

[1]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 785 Bcf or a net 114 Bcf long position. Of the net long position, basis swaps constitute 71 Bcf.
[2]	The net of total non-trading derivative assets and liabilities is a $48 million asset as shown on CERC’s Condensed Consolidated Balance Sheets, and is comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $20 million.
[3]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 633 billion cubic feet (Bcf) or a net 84 Bcf long position. Of the net long position, basis swaps constitute 74 Bcf and volumes associated with price stabilization activities of the Natural Gas Distribution business segment constitute 6 Bcf.
[4]	The net of total non-trading derivative assets and liabilities is a $55 million asset as shown on CERC’s Condensed Consolidated Balance Sheets, and is comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $56 million.
[5]	Natural gas contracts are subject to master netting arrangements and are presented on a net basis in the Condensed Consolidated Balance Sheets. This netting causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets.
[6]	The Gains (Losses) in Expense: Natural Gas includes $(17) million of costs in 2011 associated with price stabilization activities of the Natural Gas Distribution business segment that will be ultimately recovered through purchased gas adjustments. There are no such costs associated with price stabilization activities of the Natural Gas Distribution business segment in the three months ended June 30, 2012.
[7]	The Gains (Losses) in Expense: Natural Gas includes $(62) million and $(38) million of costs in 2011 and 2012, 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

6 Months Ended

Jun. 30, 2012

Jun. 30, 2011

Jun. 30, 2012

Jun. 30, 2011

Dec. 31, 2011

Statement [Line Items]

Illiquid forward price low range (per mmbtu)

$ 2.52

Illiquid forward price high range (per mmbtu)

$ 4.64

Option volatilities low range

0.00%

Option volatilities high range

90.00%

Cash collateral posted with counterparties

$ 20,000,000

$ 56,000,000

Corporate Equities

1,000,000

Investments, including money market funds

^[1]

11,000,000

Natural gas derivatives, assets

89,000,000

107,000,000

Total Assets

101,000,000

119,000,000

Natural gas derivatives, liabilities

41,000,000

52,000,000

Total liabilities

41,000,000

52,000,000

Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation Calculation Roll Forward

Beginning balance

3,000,000

$ 6,000,000

6,000,000

$ 3,000,000

Total unrealized gains

^[2]

2,000,000

1,000,000

4,000,000

Total settlements

^[2]

(2,000,000)

(6,000,000)

(2,000,000)

Transfers out of Level 3

(1,000,000)

Ending balance

^[3]

3,000,000

5,000,000

3,000,000

5,000,000

Amount Of Total Gains For Period Included In Earnings

1,000,000

$ 1,000,000

2,000,000

$ 3,000,000

Estimate of Fair Value, Fair Value Disclosure [Member]

Statement [Line Items]

Long-term Debt, Fair Value

2,981,000,000

3,272,000,000

Carrying (Reported) Amount, Fair Value Disclosure [Member]

Statement [Line Items]

Long-term Debt, Fair Value

2,637,000,000

2,919,000,000

Fair Value, Inputs, Level 1 [Member]

Statement [Line Items]

Corporate Equities

1,000,000

Investments, including money market funds

^[1]

11,000,000

Natural gas derivatives, assets

3,000,000

1,000,000

Total Assets

15,000,000

13,000,000

Natural gas derivatives, liabilities

11,000,000

19,000,000

Total liabilities

11,000,000

19,000,000

Fair Value, Inputs, Level 2 [Member]

Statement [Line Items]

Corporate Equities

Investments, including money market funds

^[1]

Natural gas derivatives, assets

71,000,000

112,000,000

Total Assets

71,000,000

112,000,000

Natural gas derivatives, liabilities

38,000,000

101,000,000

Total liabilities

38,000,000

101,000,000

Fair Value, Inputs, Level 3 [Member]

Statement [Line Items]

Corporate Equities

Investments, including money market funds

^[1]

Natural gas derivatives, assets

29,000,000

10,000,000

Total Assets

29,000,000

10,000,000

Natural gas derivatives, liabilities

26,000,000

4,000,000

Total liabilities

26,000,000

4,000,000

Netting Adjustments [Member]

Statement [Line Items]

Corporate Equities

^[4]

^[5]

Investments, including money market funds

^[1]

^[4]

^[5]

Natural gas derivatives, assets

(14,000,000)

^[4]

(14,000,000)

^[4]

(16,000,000)

^[5]

Total Assets

(14,000,000)

^[4]

(14,000,000)

^[4]

(16,000,000)

^[5]

Natural gas derivatives, liabilities

(34,000,000)

^[4]

(34,000,000)

^[4]

(72,000,000)

^[5]

Total liabilities

$ (34,000,000)

^[4]

$ (34,000,000)

^[4]

$ (72,000,000)

^[5]

[1]	Excludes money market fund investments included in Cash and cash equivalents.
[2]	CERC did not have Level 3 unrealized gain (losses) or settlements related to price stabilization activities of the Natural Gas Distribution business segment for either the three or six months ended June 30, 2011 or 2012.
[3]	During both the three and six months ended June 30, 2011 and 2012, CERC did not have Level 3 purchases, sales or significant transfers into Level 3.
[4]	Amounts represent the impact of legally enforceable master netting agreements that allow CERC to settle positive and negative positions and also include cash collateral of $20 million posted with the same counterparties.
[5]	Amounts represent the impact of legally enforceable master netting agreements that allow CERC to settle positive and negative positions and also include cash collateral of $56 million posted with the same counterparties.

Goodwill Goodwill (Details) - USD ($) $ in Millions	Jun. 30, 2012	Dec. 31, 2011
Goodwill [Line Items]
Goodwill	$ 1,696	$ 1,696
Natural Gas Distribution [Member]
Goodwill [Line Items]
Goodwill	746	746
Interstate Pipelines [Member]
Goodwill [Line Items]
Goodwill	579	579
Competitive Natural Gas Sales and Services [Member]
Goodwill [Line Items]
Goodwill	335	335
Field Services [Member]
Goodwill [Line Items]
Goodwill	25	25
Other Operations [Member]
Goodwill [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 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 2: 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 3: 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 4: 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 5: 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=6905597&loc=d3e13816-109267

Reference 6: 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 7: 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 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

Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Money Pool Borrowings	$ 414		$ 414		$ 383
Interest Income (Expense) Net, Related Party	1	$ 1	2	$ 1
Corporate service charges, related party	$ 41	$ 42	$ 81	$ 81

Short-term Borrowings and Long-term Debt (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Short-term Debt	$ 30	$ 62
Line of Credit [Member] \| CERC Corp [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 950
Revolving credit facility borrowing rate	London Interbank Offered Rate plus 150 basis points
Loans Outstanding	$ 0	0
Letters Of Credit Outstanding	0	0
Commercial Paper Outstanding	$ 0	285
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	65.00%
Product Financing Arrangement [Member]
Short-term Debt	$ 30	$ 62

Commitments and Contingencies (Details)	6 Months Ended
Commitments and Contingencies (Details)	Jun. 30, 2012 USD ($) bcf
Recorded Unconditional Purchase Obligation Payment Schedule [Abstract]
2012	$ 185,000,000
2013	428,000,000
2014	339,000,000
2015	210,000,000
2016	148,000,000
After 2016	$ 251,000,000
LegalEnvironmentalAndOtherRegulatoryMattersLegalMattersGasMarketManipulationCasesAbstract
Recovery of compensatory damages sought by plaintiffs	in excess of $1 billion
Approximate number of gas market manipulatioin lawsuits naming CenterPoint Energy 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 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	$ 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 estimated 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	5,700,000
Approximate amount of undiscounted maximum potential demand charges under the transportation contracts	82,000,000
Approximate amount of collateral posted as security on transportaion contracts	28,000,000
Long-Term Gas Gathering and Treating Agreements [Member]
Schedule of Capital Expansion Projects [Abstract]
Estimated Total Capital Expenditures For Expansion	$ 440,000,000
Total Capacity Of System After Potential Additional Expansion \| bcf	1.3

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Effective Income Tax Rate	40.00%	40.00%	39.00%	39.00%
Unrecognized Tax Benefits (Expense)	$ (11)		$ (11)		$ 8
Portion of unrecognized tax benefits that, if recognized, would reduce the effective income tax rate	6		6		6
Interest accrued on unrecognized tax benefits	$ (7)		$ (7)		$ (4)

Reportable Business Segments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Revenues	$ 846	$ 1,228	$ 2,396	$ 3,323
Segment Reporting Information, Intersegment Revenue	0	0	0	0
Operating Income (Loss)	106	114	335	374
Assets	10,467		10,467		$ 10,687
Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Revenues	360	448	1,209	1,655
Segment Reporting Information, Intersegment Revenue	6	4	11	9
Operating Income (Loss)	9	13	130	155
Assets	4,503		4,503		4,636
Competitive Natural Gas Sales and Services [Member]
Segment Reporting Information [Line Items]
Revenues	302	581	822	1,278
Segment Reporting Information, Intersegment Revenue	6	5	11	14
Operating Income (Loss)	(4)	3	(3)	13
Assets	1,023		1,023		1,089
Interstate Pipelines [Member]
Segment Reporting Information [Line Items]
Revenues	88	111	170	224
Segment Reporting Information, Intersegment Revenue	37	31	82	65
Operating Income (Loss)	52	60	112	136
Assets	3,935		3,935		3,867
Field Services [Member]
Segment Reporting Information [Line Items]
Revenues	96	88	195	166
Segment Reporting Information, Intersegment Revenue	8	10	14	22
Operating Income (Loss)	51	39	98	75
Assets	1,976		1,976		1,894
Other Operations [Member]
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Segment Reporting Information, Intersegment Revenue	0	0	0	0
Operating Income (Loss)	(2)	(1)	(2)	(5)
Assets	363		363		660
Reconciling Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Segment Reporting Information, Intersegment Revenue	(57)	(50)	(118)	(110)
Operating Income (Loss)	0	$ 0	0	$ 0
Assets	$ (1,333)		$ (1,333)		$ (1,459)

Other Current Assets and Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2012	Dec. 31, 2011
Margin Deposits	$ 17	$ 17
Under Recovered Gas Costs	102	63
Over Recovered Gas Costs	$ 11	$ 14

Subsequent Events (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
Subsequent Events (Details) - USD ($) $ in Millions	Jul. 31, 2012	Jun. 30, 2012
Ownership Interest In Waskom		50.00%
Remaining Ownership Interest in Waskom Acquired	50.00%
Total Cash Consideration	$ 275
Business Acquisition, Purchase Price Allocation, Remaining Interest	200
Pre-tax Gain from Remeasuring Original Waskom Investment	$ 130