Centerpoint Energy Resources 10-Q 5 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($)	9 Months Ended
	Sep. 30, 2015	Oct. 23, 2015	Jun. 30, 2014
Entity Information [Line Items]
Entity Registrant Name	CENTERPOINT ENERGY RESOURCES CORP
Entity Central Index Key	1,042,773
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		1,000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 0

CONDENSED STATEMENTS OF CONSOLI

CONDENSED STATEMENTS OF CONSOLIDATED INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Revenues	$ 799	$ 964	$ 3,440	$ 4,678
Expenses:
Natural gas	527	702	2,410	3,625
Operation and maintenance	165	184	541	562
Depreciation and amortization	57	53	169	153
Taxes other than income taxes	32	28	115	114
Total	781	967	3,235	4,454
Operating Income (Loss)	18	(3)	205	224
Other Income (Expense):
Interest and other finance charges	(34)	(36)	(103)	(105)
Equity in earnings (losses) of unconsolidated affiliates, net	(794)	79	(699)	241
Other, net	2	3	3	7
Total	(826)	46	(799)	143
Income (Loss) Before Income Taxes	(808)	43	(594)	367
Income tax expense (benefit)	(300)	15	(217)	139
Net Income (Loss)	$ (508)	$ 28	$ (377)	$ 228

CONDENSED STATEMENTS OF CONSOL3

CONDENSED STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (508)	$ 28	$ (377)	$ 228
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 (loss)	$ (508)	$ 28	$ (377)	$ 228

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Current Assets:
Cash and cash equivalents	$ 1	$ 2
Accounts receivable, less bad debt reserve of $18 and $23, respectively	261	595
Accrued unbilled revenue	68	262
Accounts and notes receivable–affiliated companies	75	18
Materials and supplies	49	41
Natural gas inventory	168	211
Non-trading derivative assets	78	99
Deferred income tax assets	0	1
Prepaid expenses and other current assets	41	90
Total current assets	741	1,319
Property, Plant and Equipment:
Property, plant and equipment	5,720	5,364
Less: accumulated depreciation and amortization	1,634	1,554
Property, plant and equipment, net	4,086	3,810
Other Assets:
Goodwill	840	840
Non-trading derivative assets	39	32
Investment in unconsolidated affiliates	3,604	4,521
Notes receivable from unconsolidated affiliates	363	363
Other	150	160
Total other assets	4,996	5,916
Total Assets	9,823	11,045
Current Liabilities:
Short-term borrowings	49	53
Current portion of long-term debt	325	0
Accounts payable	226	528
Accounts and notes payable–affiliated companies	33	228
Taxes accrued	60	67
Interest accrued	40	36
Customer deposits	78	80
Non-trading derivative liabilities	12	19
Other	164	137
Total current liabilities	987	1,148
Other Liabilities:
Deferred income taxes, net	2,078	2,252
Non-trading derivative liabilities	5	1
Benefit obligations	110	111
Regulatory liabilities	703	669
Other	199	194
Total other liabilities	3,095	3,227
Long-Term Debt	$ 1,917	$ 2,469
Commitments and Contingencies (Note 10)
Stockholder’s Equity:
Common stock	$ 0	$ 0
Paid-in capital	2,417	2,417
Retained earnings	1,406	1,783
Accumulated other comprehensive income	1	1
Total stockholder’s equity	3,824	4,201
Total Liabilities and Stockholder’s Equity	$ 9,823	$ 11,045

CONDENSED CONSOLIDATED BALANCE5

CONDENSED CONSOLIDATED BALANCE SHEETS Balance Sheets Parenthetical - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 18	$ 23

CONDENSED STATEMENTS OF CONSOL6

CONDENSED STATEMENTS OF CONSOLIDATED CASH FLOWS (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash Flows from Operating Activities:
Net income (loss)	$ (377)	$ 228
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	169	153
Amortization of deferred financing costs	7	7
Deferred income taxes	(162)	132
Write-down of natural gas inventory	4	2
Equity in (earnings) losses of unconsolidated affiliates, net of distributions	843	(6)
Changes in other assets and liabilities:
Accounts receivable and unbilled revenues, net	532	444
Accounts receivable/payable–affiliated companies	(64)	7
Inventory	31	(118)
Taxes receivable	0	18
Accounts payable	(302)	(220)
Fuel cost recovery	71	(57)
Interest and taxes accrued	(3)	(15)
Non-trading derivatives, net	(6)	(25)
Margin deposits, net	20	(13)
Other current assets	13	18
Other current liabilities	(12)	(8)
Other assets	11	8
Other liabilities	(9)	22
Other, net	0	5
Net cash provided by operating activities	766	582
Cash Flows from Investing Activities:
Capital expenditures	(420)	(376)
Distribution of unconsolidated affiliates in excess of cumulative earnings	74	0
Increase in notes receivable - affiliated companies	0	(83)
Other, net	3	(2)
Net cash used in investing activities	(343)	(461)
Cash Flows from Financing Activities:
Increase (decrease) in short-term borrowings, net	(4)	37
Payments of commercial paper, net	(232)	(118)
Decrease in notes payable–affiliated companies	(188)	(38)
Other, net	0	1
Net cash used in financing activities	(424)	(118)
Net Increase (Decrease) in Cash and Cash Equivalents	(1)	3
Cash and Cash Equivalents at Beginning of Period	2	1
Cash and Cash Equivalents at End of Period	1	4
Cash Payments:
Interest, net of capitalized interest	90	91
Income taxes (refunds), net	7	(1)
Non-cash transactions:
Accounts payable related to capital expenditures	37	25
Exercise of SESH put to Enable	$ 1	$ 196

Background and Basis of Present

Background and Basis of Presentation	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [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, 2014 . Background. CERC owns and operates natural gas distribution systems and owns interests in Enable Midstream Partners, LP (Enable) as described in Note 6 . A wholly-owned subsidiary of CERC Corp. offers variable and fixed-price physical natural gas supplies primarily to commercial and industrial customers and electric and gas utilities. As of September 30, 2015 , CERC Corp. also owned approximately 55.4% of the limited partner interests in Enable, which owns, operates and develops natural gas and crude oil infrastructure assets. 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 generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. 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 12 .

New Accounting Pronouncements

New Accounting Pronouncements	9 Months Ended
	Sep. 30, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	New Accounting Pronouncements In February 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis (ASU 2015-02). ASU 2015 -02 changes the analysis that reporting organizations must perform to evaluate whether they should consolidate certain legal entities, such as limited partnerships. The changes include, among others, modification of the evaluation of whether limited partnerships and similar legal entities are variable interest entities (VIEs) or voting interest entities and elimination of the presumption that a general partner should consolidate a limited partnership. ASU 2015-02 does not amend the related party guidance for situations in which power is shared between two or more entities that hold interests in a VIE. ASU 2015 -02 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2015. CERC will adopt ASU 2015-02 on January 1, 2016 and is currently assessing the impact, if any, that this standard will have on its financial position, results of operations, cash flows and disclosures. In April 2015, the FASB issued Accounting Standards Update No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Cost (ASU 2015-03) . ASU 2015-03 requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by ASU 2015-03. CERC will adopt ASU 2015-03 retrospectively on January 1, 2016, which will result in a reduction of both other long-term assets and long-term debt on its Condensed Consolidated Balance Sheets. CERC had debt issuance costs of $16 million and $18 million included in other long-term assets on its Condensed Consolidated Balance Sheets as of September 30, 2015 and December 31, 2014 , respectively. In April 2015, the FASB issued Accounting Standards Update No. 2015-05, Intangibles-Goodwill and Other-Internal-Use Software ( Subtopic 350-40 ) (ASU 2015-05). ASU 2015-05 provides guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The guidance will not change a customer’s accounting for service contracts. ASU 2015-05 is effective for fiscal years, and interim periods within the fiscal years, beginning after December 15, 2015 and may be adopted either prospectively or retrospectively. CERC will adopt ASU 2015-05 on January 1, 2016 and is currently assessing the impact that this standard will have on its financial position, results of operations, cash flows and disclosures. In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) (ASU 2014-09), which supersedes most current revenue recognition guidance. ASU 2014-09 provides a comprehensive new revenue recognition model that requires revenue to be recognized in a manner that depicts the transfer of goods or services to a customer at an amount that reflects the consideration expected to be received in exchange for those goods or services. ASU 2014-09 was initially effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is not permitted, and entities have the option of using either a full retrospective or a modified retrospective adoption approach. In August 2015, the FASB issued Accounting Standard Update No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date , which delays the effective date of ASU 2014-09 by one year. CERC is currently evaluating the impact that ASU 2014-09 will have on its financial position, results of operations, cash flows and disclosures, and may adopt ASU 2014-09 on January 1, 2018 as permitted by the new guidance. In July 2015, the FASB issued Accounting Standards Update No. 2015-11, Inventory (Topic 330) Simplifying the Measurement of Inventory (ASU 2015-11). ASU 2015-11 changes the subsequent measurement guidance for inventory accounted for using methods other than the last in, first out (LIFO) and Retail Inventory methods. Companies will subsequently measure inventory at the lower of cost and net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. Subsequent measurement is unchanged for inventory measured using LIFO or the retail inventory method. ASU 2015-11 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, with early adoption permitted. CERC does not believe that ASU 2015-11 will have a material impact on its financial position, results of operations, cash flows and disclosures. Management believes that other recently issued standards, which are not yet effective, will not have a material impact on CERC’s consolidated financial position, results of operations or cash flows upon adoption.

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Pension and Other Postretirement Benefits Disclosure [Text Block]	Employee Benefit Plans 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 Nine Months Ended September 30, September 30, 2015 2014 2015 2014 (in millions) Service cost $ 1 $ 1 $ 1 $ 1 Interest cost on accumulated benefit obligation 2 1 $ 4 $ 4 Expected return on plan assets (1 ) (1 ) (1 ) (1 ) Amortization of loss — 1 1 1 Net periodic cost $ 2 $ 2 $ 5 $ 5 CERC expects to contribute approximately $7 million to its postretirement benefit plan in 2015 , of which $1 million and $4 million were contributed during the three and nine months ended September 30, 2015 , respectively.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	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 Condensed 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 sale if the intent is to physically receive or deliver the product for use or sale in the normal course of business. CenterPoint Energy has a Risk Oversight Committee composed of corporate and business segment officers that oversees commodity price, weather and credit risk activities, including 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 the use of new products and commodities, monitor positions and ensure compliance with CERC’s risk management policies, 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 risk and does not engage in proprietary or speculative commodity trading. These financial instruments do not qualify or are not designated as cash flow or fair value hedges. Weather Hedges. CERC has weather normalization or other rate mechanisms that mitigate the impact of weather on its natural gas distribution business (NGD) in Arkansas, Louisiana, Mississippi, Minnesota and Oklahoma. NGD in Texas does not have such mechanisms. As a result, fluctuations from normal weather may have a positive or negative effect on NGD’s results in Texas. CERC has historically entered into heating-degree day swaps for certain NGD jurisdictions to mitigate the effect of fluctuations from normal weather on its results of operations and cash flows for the winter heating season, which contained a bilateral dollar cap of $16 million in both 2013–2014 and 2014–2015. However, NGD did not enter into heating-degree day swaps for the 2015–2016 winter season as a result of NGD’s Minnesota division implementing a full decoupling pilot in July 2015. The swaps are based on ten -year normal weather. During both the three months ended September 30, 2015 and 2014 , CERC recognized no losses related to these swaps. During the nine months ended September 30, 2015 and 2014 , CERC recognized losses of $4 million and $7 million , respectively, related to these swaps. Weather hedge gains and losses are included in revenues in the Condensed Statements of Consolidated Income. (b) Derivative Fair Values and Income Statement Impacts The following tables present information about CERC’s derivative instruments and hedging activities. The first four tables provide a balance sheet overview of CERC’s Derivative Assets and Liabilities as of September 30, 2015 and December 31, 2014 , while the last two tables provide a breakdown of the related income statement impacts for the three and nine months ended September 30, 2015 and 2014 . Fair Value of Derivative Instruments September 30, 2015 Total derivatives not designated as hedging instruments Balance Sheet Location Derivative Assets Fair Value Derivative Liabilities Fair Value (in millions) Natural gas derivatives (1) (2) Current Assets: Non-trading derivative assets $ 80 $ 2 Natural gas derivatives (1) (2) Other Assets: Non-trading derivative assets 39 — Natural gas derivatives (1) (2) Current Liabilities: Non-trading derivative liabilities 16 59 Natural gas derivatives (1) (2) Other Liabilities: Non-trading derivative liabilities 3 24 Total $ 138 $ 85 (1) The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 776 billion cubic feet (Bcf) or a net 77 Bcf long position. Of the net long position, basis swaps constitute 128 Bcf. (2) Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was a $100 million asset as shown on CERC’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $47 million . Offsetting of Natural Gas Derivative Assets and Liabilities September 30, 2015 Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) (in millions) Current Assets: Non-trading derivative assets $ 96 $ (18 ) $ 78 Other Assets: Non-trading derivative assets 42 (3 ) 39 Current Liabilities: Non-trading derivative liabilities (61 ) 49 (12 ) Other Liabilities: Non-trading derivative liabilities (24 ) 19 (5 ) Total $ 53 $ 47 $ 100 (1) Gross amounts recognized include some derivative assets and liabilities that are not subject to master netting arrangements. (2) The derivative assets and liabilities on the Condensed Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default. Fair Value of Derivative Instruments December 31, 2014 Total derivatives not designated as hedging instruments Balance Sheet Location Derivative Assets Fair Value Derivative Liabilities Fair Value (in millions) Natural gas derivatives (1) (2) Current Assets: Non-trading derivative assets $ 101 $ 1 Natural gas derivatives (1) (2) Other Assets: Non-trading derivative assets 32 — Natural gas derivatives (1) (2) Current Liabilities: Non-trading derivative liabilities 14 83 Natural gas derivatives (1) (2) Other Liabilities: Non-trading derivative liabilities 2 18 Total $ 149 $ 102 (1) The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 804 Bcf or a net 60 Bcf long position. Of the net long position, basis swaps constitute 127 Bcf. (2) Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was a $111 million asset as shown on CERC’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above, offset by collateral netting of $64 million . Offsetting of Natural Gas Derivative Assets and Liabilities December 31, 2014 Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) (in millions) Current Assets: Non-trading derivative assets $ 115 $ (16 ) $ 99 Other Assets: Non-trading derivative assets 34 (2 ) 32 Current Liabilities: Non-trading derivative liabilities (84 ) 65 (19 ) Other Liabilities: Non-trading derivative liabilities (18 ) 17 (1 ) Total $ 47 $ 64 $ 111 (1) Gross amounts recognized include some derivative assets and liabilities that are not subject to master netting arrangements. (2) The derivative assets and liabilities on the Condensed Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default. Realized and unrealized gains and losses on derivatives are recognized in the Condensed Statements of Consolidated Income as revenue for retail sales derivative contracts and as natural gas expense for financial natural gas derivatives and non-retail related physical natural gas derivatives. Income Statement Impact of Derivative Activity Three Months Ended September 30, Total derivatives not designated as hedging instruments Income Statement Location 2015 2014 (in millions) Natural gas derivatives Gains (Losses) in Revenue $ 39 $ 22 Natural gas derivatives (1) Gains (Losses) in Expense: Natural Gas (30 ) (4 ) Total $ 9 $ 18 (1) The Gains (Losses) in Expense: Natural Gas includes $-0- during each of the three months ended September 30, 2015 and 2014 , related to physical forwards purchased from Enable. Income Statement Impact of Derivative Activity Nine Months Ended September 30, Total derivatives not designated as hedging instruments Income Statement Location 2015 2014 (in millions) Natural gas derivatives Gains (Losses) in Revenue $ 88 $ (74 ) Natural gas derivatives (1) Gains (Losses) in Expense: Natural Gas (72 ) 110 Total $ 16 $ 36 (1) The Gains (Losses) in Expense: Natural Gas includes $-0- and $2 million during the nine months ended September 30, 2015 and 2014 , respectively, related to physical forwards purchased from Enable. (c) Credit Risk Contingent Features 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 September 30, 2015 and December 31, 2014 was $3 million and $2 million , respectively. CERC posted no assets as collateral towards derivative instruments that contain credit risk contingent features at either September 30, 2015 or December 31, 2014 . If all derivative contracts (in a net liability position) containing credit risk contingent features were triggered at September 30, 2015 and December 31, 2014 , $3 million and $2 million , respectively, of additional assets would be required to be posted as collateral.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	Fair Value Measurements Assets and liabilities that are recorded at fair value in the Condensed Consolidated Balance Sheets are categorized based upon the level of judgment associated with the inputs used to measure their value. Hierarchical levels, as defined below and directly related to the amount of subjectivity associated with the inputs to fair valuations of these assets and liabilities, are as follows: Level 1: Inputs are unadjusted quoted prices in active markets for identical assets or liabilities at the measurement date. The types of assets carried at Level 1 fair value 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. At September 30, 2015 , 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 $1.17 to $3.78 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% to 76% ) 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. For the nine months ended September 30, 2015 , there were no transfers between Level 1 and 2. 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 September 30, 2015 and December 31, 2014 , 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 September 30, 2015 (in millions) Assets Corporate equities $ 2 $ — $ — $ — $ 2 Investments, including money market funds (2) 11 — — — 11 Natural gas derivatives 5 111 22 (21 ) 117 Total assets $ 18 $ 111 $ 22 $ (21 ) $ 130 Liabilities Natural gas derivatives $ 14 $ 63 $ 8 $ (68 ) $ 17 Total liabilities $ 14 $ 63 $ 8 $ (68 ) $ 17 (1) Amounts represent the impact of legally enforceable master netting arrangements that allow CERC to settle positive and negative positions and also include cash collateral of $47 million posted with the same counterparties. (2) Amounts are included in Prepaid Expenses and Other Current Assets in the Condensed Consolidated Balance Sheets. 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, 2014 (in millions) Assets Corporate equities $ 2 $ — $ — $ — $ 2 Investments, including money market funds (2) 11 — — — 11 Natural gas derivatives 7 122 20 (18 ) 131 Total assets $ 20 $ 122 $ 20 $ (18 ) $ 144 Liabilities Natural gas derivatives $ 22 $ 77 $ 3 $ (82 ) $ 20 Total liabilities $ 22 $ 77 $ 3 $ (82 ) $ 20 (1) Amounts represent the impact of legally enforceable master netting arrangements that allow CERC to settle positive and negative positions and also include cash collateral of $64 million posted with the same counterparties. (2) Amounts are included in Prepaid Expenses and Other Current Assets in the Condensed Consolidated Balance Sheets. The following table presents 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 September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Beginning balance $ 10 $ 4 $ 17 $ 3 Total gains 5 6 5 6 Total settlements (2 ) (1 ) (8 ) 1 Transfers into Level 3 1 — 1 (1 ) Transfers out of Level 3 — — (1 ) — Ending balance (1) $ 14 $ 9 $ 14 $ 9 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 $ 6 $ 6 $ 7 $ 7 (1) CERC did not have significant Level 3 purchases or sales during either of the three or nine months ended September 30, 2015 or 2014 . Items Measured at Fair Value on a Nonrecurring Basis Based on the sustained low Enable common unit price and further declines in such price during the three months ended September 30, 2015 as well as the market outlook for continued depressed crude oil and natural gas prices impacting the midstream oil and gas industry, CERC determined in connection with its preparation of financial statements for the three months ended September 30, 2015, that an other than temporary decrease in the value of its investment in Enable had occurred. The impairment analysis compared the estimated fair value of CERC’s investment in Enable to its carrying value. The fair value of the investment was determined using multiple valuation methodologies under both the market and income approaches. Both of these approaches incorporate significant estimates and assumptions, including: Market Approach • quoted price of Enable’s common units; • recent market transactions of comparable companies; and • EBITDA to total enterprise multiples for comparable companies. Income Approach • Enable’s forecasted cash distributions; • projected cash flows of incentive distribution rights; • forecasted growth rate of Enable’s cash distributions; and • determination of the cost of equity, including market risk premiums. Weighting of the different approaches Significant unobservable inputs used include the growth rate applied to the projected cash distributions beyond 2020 and the discount rate used to determine the present value of the estimated future cash flows. Based on the significant unobservable estimates and assumptions required, CERC concluded that the fair value estimate should be classified as a Level 3 measurement within the fair value hierarchy. As a result of the analysis, CERC recorded an other than temporary impairment on its investment in Enable of $250 million , reducing the fair value of the investment to $3.6 billion . See Note 6 for further discussion of the impairment. As of December 31, 2014, there were no significant assets or liabilities measured at fair value on a nonrecurring basis. 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 or Level 2 in the fair value hierarchy. September 30, 2015 December 31, 2014 Carrying Fair Carrying Amount Fair Value (in millions) Financial assets: Notes receivable from unconsolidated affiliates $ 363 $ 362 $ 363 $ 362 Financial liabilities: Long-term debt $ 2,242 $ 2,460 $ 2,469 $ 2,772

Unconsolidated Affiliates (Note

Unconsolidated Affiliates (Notes)	9 Months Ended
	Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures Disclosure [Text Block]	Unconsolidated Affiliates On May 1, 2013 (the Closing Date) CERC Corp., OGE Energy Corp. (OGE) and ArcLight Capital Partners, LLC closed on the formation of Enable. CERC has the ability to significantly influence the operating and financial policies of Enable and, accordingly, accounts for its investment in Enable using the equity method of accounting. CERC’s maximum exposure to loss related to Enable, a VIE in which CERC is not the primary beneficiary, is limited to its equity investment as presented in the Condensed Consolidated Balance Sheet at September 30, 2015 , CERC Corp.’s guarantee of collection of Enable’s $1.1 billion senior notes due 2019 and 2024 (Guaranteed Senior Notes) and other guarantees discussed in Note 10 , CERC Corp.’s $363 million notes receivable from Enable and outstanding current accounts receivable from Enable. The $363 million of notes receivable from Enable bears interest at an annual rate of 2.10% to 2.45% and matures in 2017. CERC recorded interest income of $2 million during each of the three months ended September 30, 2015 and 2014 , and $6 million during each of the nine months ended September 30, 2015 and 2014 , and had interest receivable from Enable of $2 million and $4 million as of September 30, 2015 and December 31, 2014 , respectively, on its notes receivable. Effective on the Closing Date, CenterPoint Energy and Enable entered into a Services Agreement, Employee Transition Agreement, Transitional Seconding Agreement and other agreements (Transition Agreements). Under the Services Agreement, CERC agreed to provide certain support services to Enable such as accounting, legal, risk management and treasury functions for an initial term. The initial term of the Services Agreement ends on April 30, 2016, after which date such services continue on a year-to-year basis unless terminated by Enable with at least 90 days’ notice. Enable may terminate the Services Agreement, or the provision of any services thereunder, upon approval by its board of directors and at least 180 days’ notice. CERC provided seconded employees to Enable to support its operations for a term ending on December 31, 2014. Enable, at its discretion, had the right to select and offer employment to seconded employees from CERC. During the fourth quarter of 2014, Enable notified CERC that it provided employment offers to substantially all of the seconded employees from CERC. Substantially all of the seconded employees became employees of Enable effective January 1, 2015. In accordance with the Enable formation agreements, CERC had certain put rights, and Enable had certain call rights, exercisable with respect to the 25.05% interest in Southeast Supply Header, LLC (SESH) retained by CERC on the Closing Date, under which CERC would contribute its retained interest in SESH, in exchange for a specified number of limited partner common units in Enable and a cash payment, payable either from CERC to Enable or from Enable to CERC, to the extent of changes in the value of SESH subject to certain restrictions. Specifically, the rights were exercisable with respect to (1) a 24.95% interest in SESH, which closed on May 30, 2014 and (2) a 0.1% interest in SESH, which closed on June 30, 2015 . CERC billed Enable for reimbursement of transition services, including the costs of seconded employees, $3 million and $36 million during the three months ended September 30, 2015 and 2014 , respectively, and $10 million and $118 million during the nine months ended September 30, 2015 and 2014 , respectively, under the Transition Agreements. Actual transition services costs are recorded net of reimbursements received from Enable. CERC had accounts receivable from Enable of $4 million and $28 million as of September 30, 2015 and December 31, 2014 , respectively, for amounts billed for transition services, including the cost of seconded employees. CERC incurred natural gas expenses, including transportation and storage costs, of $23 million and $24 million during the three months ended September 30, 2015 and 2014 , respectively, and $87 million and $99 million during the nine months ended September 30, 2015 and 2014 , respectively, for transactions with Enable. CERC had accounts payable to Enable of $8 million and $23 million at September 30, 2015 and December 31, 2014 , respectively, from such transactions. As of September 30, 2015 , CERC held an approximate 55.4% limited partner interest in Enable, consisting of 94,151,707 common units and 139,704,916 subordinated units. As of September 30, 2015, CERC and OGE each own a 50% management interest in the general partner of Enable and a 40% and 60% interest, respectively, in the incentive distribution rights held by the general partner. CERC recognized a loss of $794 million from its investment in Enable for the three months ended September 30, 2015. This loss included impairment charges totaling $862 million composed of CERC’s impairment of its investment in Enable of $250 million and CERC’s share, $612 million , of impairment charges Enable recorded for goodwill and long-lived assets. CERC evaluates its equity method investments for impairment when factors indicate that a decrease in the value of its investment has occurred and the carrying amount of its investment may not be recoverable. An impairment loss, based on the excess of the carrying value over estimated fair value of the investment, is recognized in earnings when an impairment is deemed to be other than temporary. Considerable judgment is used in determining if an impairment loss is other than temporary and the amount of any impairment. Based on the sustained low Enable common unit price and further declines in such price during the three months ended September 30, 2015 as well as the market outlook for continued depressed crude oil and natural gas prices impacting the midstream oil and gas industry, CERC determined in connection with its preparation of financial statements for the three months ended September 30, 2015, that an other than temporary decrease in the value of its investment in Enable had occurred. CERC wrote down the value of its investment in Enable to its estimated fair value of $3.6 billion which resulted in an impairment charge of $250 million as of September 30, 2015. Both the income approach and market approach were utilized to estimate the fair value of CERC’s total investment in Enable, which includes the limited partner common and subordinated units, general partner interest and incentive distribution rights held by CERC. The determination of fair value considered a number of relevant factors including Enable’s common unit price and forecasted results, recent comparable transactions and the limited float of Enable’s publicly traded common units. See Note 5 for further discussion of the determination of fair value of CERC’s investment in Enable. Investment in Unconsolidated Affiliates: September 30, December 31, 2014 (in millions) Enable $ 3,604 $ 4,520 SESH (1) — 1 Total $ 3,604 $ 4,521 (1) CERC disposed of its remaining interest in SESH on June 30, 2015. Equity in Earnings (Losses) of Unconsolidated Affiliates, net: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Enable $ (794 ) $ 79 $ (699 ) $ 236 SESH (1) — — — 5 Total $ (794 ) $ 79 $ (699 ) $ 241 (1) CERC disposed of its remaining interest in SESH on June 30, 2015. Summarized unaudited consolidated income information for Enable is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Operating revenues $ 646 $ 804 $ 1,852 $ 2,632 Cost of sales, excluding depreciation and amortization 287 439 856 1,550 Impairment of goodwill and other long-lived assets 1,105 1 1,105 1 Operating income (loss) (975 ) 151 (778 ) 452 Net income (loss) attributable to Enable (985 ) 139 (817 ) 408 Reconciliation of Equity in Earnings (Losses), net: CERC’s interest $ (546 ) $ 76 $ (453 ) $ 230 Basis difference accretion 2 3 4 6 Impairment of CERC’s equity method investment in Enable (250 ) — (250 ) — CERC’s equity in earnings (losses), net (1) $ (794 ) $ 79 $ (699 ) $ 236 (1) These amounts include CERC’s share of Enable’s impairment of goodwill and long-lived assets and the impairment of CERC’s equity method investment in Enable totaling $862 million during the three and nine months ended September 30, 2015. This impairment is offset by $68 million and $163 million of earnings for the three and nine months ended September 30, 2015, respectively. Summarized unaudited consolidated balance sheet information for Enable is as follows: September 30, December 31, 2014 (in millions) Current assets $ 427 $ 438 Non-current assets 10,774 11,399 Current liabilities 804 671 Non-current liabilities 2,786 2,343 Non-controlling interest 25 31 Enable partners’ capital 7,586 8,792 Reconciliation of Investment in Enable: CERC’s ownership interest in Enable partners’ capital $ 4,200 $ 4,869 CERC’s existing basis difference (346 ) (349 ) Impairment of CERC’s equity method investment in Enable (250 ) — CERC’s investment in Enable $ 3,604 $ 4,520 Distributions Received from Unconsolidated Affiliates: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Enable $ 74 $ 70 $ 219 $ 227 SESH (1) — 1 — 8 Total $ 74 $ 71 $ 219 $ 235 (1) CERC disposed of its remaining interest in SESH on June 30, 2015.

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	Goodwill Goodwill by reportable business segment as of both September 30, 2015 and December 31, 2014 is as follows: (in millions) Natural Gas Distribution $ 746 Energy Services 83 Other Operations 11 Total $ 840 CERC performs goodwill impairment tests at least annually and evaluates goodwill when events or changes in circumstances indicate that its carrying value may not be recoverable. The impairment evaluation for goodwill is performed by using a two-step process. In the first step, the fair value of each reporting unit is compared with the carrying amount of the reporting unit, including goodwill. The estimated fair value of the reporting unit is generally determined on the basis of discounted cash flows. If the estimated fair value of the reporting unit is less than the carrying amount of the reporting unit, then a second step must be completed to determine the amount of the goodwill impairment that should be recorded. In the second step, the implied fair value of the reporting unit’s goodwill is determined by allocating the reporting unit’s fair value to all of its assets and liabilities other than goodwill (including any unrecognized intangible assets) in a manner similar to a purchase price allocation. The resulting implied fair value of the goodwill that results from the application of this second step is then compared to the carrying amount of the goodwill and an impairment charge is recorded for the difference. CERC performed its annual goodwill impairment test in the third quarter of 2015 and determined, based on the results of the first step, that no goodwill impairment charge was required for any reportable segment.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2015
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 borrowings from the money pool of $-0- and $188 million at September 30, 2015 and December 31, 2014 , respectively, which are included in accounts and notes payable–affiliated companies in the Consolidated Balance Sheets. Net interest income (expense) related to accounts and notes payables–affiliated companies was not material for either the three or nine months ended September 30, 2015 or 2014 . CenterPoint Energy provides some corporate services to 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 as follows and are included primarily in operation and maintenance expenses: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Corporate service charges $ 29 $ 34 $ 88 $ 93 See Note 6 for related party transactions with Enable.

Short-term Borrowings and Long-

Short-term Borrowings and Long-term Debt	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Short-term Borrowings and Long-term Debt	Short-term Borrowings and Long-term Debt (a) Short-term Borrowings Inventory Financing . NGD has asset management agreements associated with its utility distribution service in Arkansas, north Louisiana and Oklahoma that extend through 2018. Pursuant to the provisions of the agreements, NGD sells natural gas and agrees to repurchase an equivalent amount of natural gas during the winter heating seasons at the same cost, plus a financing charge. These transactions are accounted for as a financing and they had an associated principal obligation of $49 million and $53 million as of September 30, 2015 and December 31, 2014 , respectively. (b) Long-term Debt Revolving Credit Facility. As of September 30, 2015 and December 31, 2014 , CERC had the following revolving credit facility and utilization of such facility: September 30, 2015 December 31, 2014 Size of Loans Letters Commercial Loans Letters Commercial (in millions) $ 600 $ — $ 2 $ 109 $ — $ — $ 341 CERC Corp.’s $600 million revolving credit facility, which is scheduled to terminate on September 9, 2019, can be drawn at the London Interbank Offered Rate plus 1.50% based on CERC Corp.’s current credit ratings. The revolving credit facility contains a financial covenant which limits CERC’s consolidated debt to an amount not to exceed 65% of CERC’s consolidated capitalization. CERC Corp. was in compliance with all financial covenants as of September 30, 2015 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [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 Energy Services business segments, which have various quantity requirements and durations, that are not classified as non-trading derivative assets and liabilities in CERC’s Consolidated Balance Sheets as of September 30, 2015 and December 31, 2014 as these contracts meet an exception as “normal purchases contracts” or do not meet the definition of a derivative. Natural gas supply commitments also include natural gas transportation contracts that do not meet the definition of a derivative. As of September 30, 2015 , minimum payment obligations for natural gas supply commitments are approximately $159 million for the remaining three months in 2015, $489 million in 2016, $466 million in 2017, $413 million in 2018, $224 million in 2019 and $128 million after 2019. (b) Legal, Environmental and Other Regulatory Matters Legal Matters Gas Market Manipulation Cases . CenterPoint Energy, CenterPoint Energy Houston Electric, LLC (CenterPoint Houston) or their predecessor, Reliant Energy, Incorporated (Reliant Energy), and certain of their former subsidiaries have been named as defendants in certain lawsuits described below. Under a master separation agreement between CenterPoint Energy and a former subsidiary, Reliant Resources, Inc. (RRI), CenterPoint Energy and its subsidiaries are entitled to be indemnified by RRI and its successors for any losses, including certain attorneys’ fees and other costs, arising out of these lawsuits. In May 2009, RRI sold its Texas retail business to a subsidiary of NRG and RRI changed its name to RRI Energy, Inc. In December 2010, Mirant Corporation merged with and became a wholly-owned subsidiary of RRI, and RRI changed its name to GenOn Energy, Inc. (GenOn). In December 2012, NRG acquired GenOn through a merger in which GenOn became a wholly-owned subsidiary of NRG. None of the sale of the retail business, the merger with Mirant Corporation, or the acquisition of GenOn by NRG alters RRI’s (now GenOn’s) contractual obligations to indemnify CenterPoint Energy and its subsidiaries, including CenterPoint Houston, for certain liabilities, including their indemnification obligations regarding the gas market manipulation litigation, nor does it affect the terms of existing guarantee 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 and its affiliates have since been released or dismissed from all but one such case. CenterPoint Energy Services, Inc. (CES), a subsidiary of CERC Corp., is a defendant in a case now pending in federal court in Nevada alleging a conspiracy to inflate Wisconsin natural gas prices in 2000–2002. In July 2011, the court issued an order dismissing the plaintiffs’ claims against other defendants in the case, each of whom had demonstrated Federal Energy Regulatory Commission jurisdictional sales for resale during the relevant period, based on federal preemption, and stayed the remainder of the case pending outcome of the appeals. The plaintiffs appealed this ruling to the U.S. Court of Appeals for the Ninth Circuit, which reversed the trial court’s dismissal of the plaintiffs’ claims. The U.S. Supreme Court agreed to review the case, and on April 21, 2015, affirmed the Ninth Circuit’s ruling and remanded the case to the district court for further proceedings. CenterPoint Energy and CES intend to continue vigorously defending against the plaintiffs’ claims on remand. CERC does not expect the ultimate outcome of this matter to have a material adverse effect on its financial condition, results of operations or cash flows. Environmental Matters Manufactured Gas Plant Sites. CERC and its predecessors operated manufactured gas plants (MGPs) in the past. There are seven MGP sites in CERC’s Minnesota service territory. CERC believes it never owned or operated, and therefore has no liability with respect to, two of these sites. With respect to two other sites, CERC has completed state-ordered remediation, other than ongoing monitoring and water treatment. At September 30, 2015 , CERC had a recorded liability of $7 million for remediation of these five Minnesota sites. The estimated range of possible remediation costs for the sites for which CERC believes it may have responsibility was $4 million to $28 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. In addition to the Minnesota sites, the U.S. Environmental Protection Agency and other regulators have investigated MGP sites that were owned or operated by CERC or that may have been owned by one of its former affiliates. CERC and CenterPoint Energy do not expect the ultimate outcome of these investigations to have a material adverse effect on the financial condition, results of operations or cash flows of either CenterPoint Energy or CERC. Asbestos. Some facilities owned by 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, based on its experience to date, does not expect these matters, either individually or in the aggregate, to have a material adverse effect on its financial condition, results of operations or cash flows. Other Environmental. From time to time 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. From time to time, CERC is also a defendant in legal proceedings with respect to claims brought by various plaintiffs against broad groups of participants in the energy industry. Some of these proceedings involve substantial amounts. 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. (c) Guarantees 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 guarantees 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 guarantees 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 guarantees 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 $31 million as of September 30, 2015 . Based on market conditions in the fourth quarter of 2015 at the time the most recent annual calculation was made under the agreement, GenOn was not obligated to post any security. If GenOn should fail to perform the contractual obligations, CERC could have to honor its guarantee and, in such event, any collateral then provided as security may be insufficient to satisfy CERC’s obligations. CERC Corp. has also provided a guarantee of collection of $1.1 billion of Enable’s Guaranteed Senior Notes. This guarantee is subordinated to all senior debt of CERC Corp. and is subject to automatic release on May 1, 2016. The fair value of these guarantees is not material.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective tax rate reported for the three months ended September 30, 2015 was 37% compared to 35% for the same period in 2014. For the three months ended September 30, 2014, CERC recognized a tax benefit of $2 million based on the reversal of previously accrued taxes as a result of CenterPoint Energy’s filing of its 2013 consolidated federal income tax return. The effective tax rate reported for the nine months ended September 30, 2015 was 37% compared to 38% for the same period in 2014. The impairment loss reduced the deferred tax liability on CERC’s investment in Enable. CERC reported no uncertain tax liability as of September 30, 2015 and expects no significant change to the uncertain tax liability over the twelve-month period ending September 30, 2016. Tax years through 2013 have been audited and settled with the Internal Revenue Service (IRS). For 2014 and 2015, CenterPoint Energy is a participant in the IRS’s Compliance Assurance Process.

Reportable Business Segments

Reportable Business Segments	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Reportable Business Segments	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, Energy Services, Midstream Investments 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. Energy Services represents CERC’s non-rate regulated gas sales and services operations. Midstream Investments consists of CERC’s investment in Enable. The Other Operations business segment includes unallocated corporate costs and inter-segment eliminations. Financial data for business segments is as follows: For the Three Months Ended September 30, 2015 Revenues from Inter-segment Operating (in millions) Natural Gas Distribution $ 353 $ 6 $ 11 Energy Services 446 6 7 Midstream Investments (1) — — — Other Operations — — — Reconciling Eliminations — (12 ) — Consolidated $ 799 $ — $ 18 For the Three Months Ended September 30, 2014 Revenues from Inter-segment Operating (in millions) Natural Gas Distribution $ 375 $ 7 $ (8 ) Energy Services 589 15 6 Midstream Investments (1) — — — Other Operations — — (1 ) Reconciling Eliminations — (22 ) — Consolidated $ 964 $ — $ (3 ) For the Nine Months Ended September 30, 2015 Revenues from External Customers Inter-segment Revenues Operating Income Total Assets as of September 30, 2015 (in millions) Natural Gas Distribution $ 1,958 $ 21 $ 176 $ 5,360 Energy Services 1,482 28 29 852 Midstream Investments (1) — — — 3,604 Other Operations — — — 759 Reconciling Eliminations — (49 ) — (752 ) Consolidated $ 3,440 $ — $ 205 $ 9,823 For the Nine Months Ended September 30, 2014 Revenues from Inter-segment Operating Total Assets as of December 31, 2014 (in millions) Natural Gas Distribution $ 2,379 $ 22 $ 184 $ 5,464 Energy Services 2,298 66 43 978 Midstream Investments (1) — — — 4,521 Other Operations 1 — (3 ) 1,046 Reconciling Eliminations — (88 ) — (964 ) Consolidated $ 4,678 $ — $ 224 $ 11,045 (1) Midstream Investments’ equity earnings (losses) are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Enable (1) $ (794 ) $ 79 $ (699 ) $ 236 SESH — — — 5 Total $ (794 ) $ 79 $ (699 ) $ 241 (1) These amounts include CERC’s share of Enable’s impairment of goodwill and long-lived assets and the impairment of CERC’s equity method investment in Enable totaling $862 million during the three and nine months ended September 30, 2015. This impairment is offset by $68 million and $163 million of earnings for the three and nine months ended September 30, 2015, respectively. Midstream Investments’ total assets are as follows: September 30, December 31, 2014 (in millions) Enable $ 3,604 $ 4,520 SESH — 1 Total $ 3,604 $ 4,521

Other Current Assets and Liabil

Other Current Assets and Liabilities	9 Months Ended
	Sep. 30, 2015
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 September 30, 2015 and December 31, 2014 were $16 million and $19 million , respectively, of margin deposits and $8 million and $45 million , respectively, of under-recovered gas cost. Included in other current liabilities on the Condensed Consolidated Balance Sheets at September 30, 2015 and December 31, 2014 were $78 million and $37 million , respectively, of over-recovered gas cost.

Subsequent Events (Notes)

Subsequent Events (Notes)	9 Months Ended
	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events On October 22, 2015 , Enable declared a quarterly cash distribution of $0.318 per unit on all of its outstanding common and subordinated units for the quarter ended September 30, 2015. Accordingly, CERC Corp. expects to receive a cash distribution of approximately $74 million from Enable in the fourth quarter of 2015 to be made with respect to CERC Corp.’s limited partner interest in Enable for the third quarter of 2015.

Employee Benefit Plans Employee

Employee Benefit Plans Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2015
Compensation and Retirement Disclosure [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 Nine Months Ended September 30, September 30, 2015 2014 2015 2014 (in millions) Service cost $ 1 $ 1 $ 1 $ 1 Interest cost on accumulated benefit obligation 2 1 $ 4 $ 4 Expected return on plan assets (1 ) (1 ) (1 ) (1 ) Amortization of loss — 1 1 1 Net periodic cost $ 2 $ 2 $ 5 $ 5

Derivative Instruments Derivati

Derivative Instruments Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments, Offsetting Assets and Liabilities [Table Text Block]	Offsetting of Natural Gas Derivative Assets and Liabilities September 30, 2015 Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) (in millions) Current Assets: Non-trading derivative assets $ 96 $ (18 ) $ 78 Other Assets: Non-trading derivative assets 42 (3 ) 39 Current Liabilities: Non-trading derivative liabilities (61 ) 49 (12 ) Other Liabilities: Non-trading derivative liabilities (24 ) 19 (5 ) Total $ 53 $ 47 $ 100 (1) Gross amounts recognized include some derivative assets and liabilities that are not subject to master netting arrangements. (2) The derivative assets and liabilities on the Condensed Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default. Offsetting of Natural Gas Derivative Assets and Liabilities December 31, 2014 Gross Amounts Recognized (1) Gross Amounts Offset in the Consolidated Balance Sheets Net Amount Presented in the Consolidated Balance Sheets (2) (in millions) Current Assets: Non-trading derivative assets $ 115 $ (16 ) $ 99 Other Assets: Non-trading derivative assets 34 (2 ) 32 Current Liabilities: Non-trading derivative liabilities (84 ) 65 (19 ) Other Liabilities: Non-trading derivative liabilities (18 ) 17 (1 ) Total $ 47 $ 64 $ 111 (1) Gross amounts recognized include some derivative assets and liabilities that are not subject to master netting arrangements. (2) The derivative assets and liabilities on the Condensed Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default.
Fair Value of Derivative Instruments Table	Fair Value of Derivative Instruments December 31, 2014 Total derivatives not designated as hedging instruments Balance Sheet Location Derivative Assets Fair Value Derivative Liabilities Fair Value (in millions) Natural gas derivatives (1) (2) Current Assets: Non-trading derivative assets $ 101 $ 1 Natural gas derivatives (1) (2) Other Assets: Non-trading derivative assets 32 — Natural gas derivatives (1) (2) Current Liabilities: Non-trading derivative liabilities 14 83 Natural gas derivatives (1) (2) Other Liabilities: Non-trading derivative liabilities 2 18 Total $ 149 $ 102 (1) The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 804 Bcf or a net 60 Bcf long position. Of the net long position, basis swaps constitute 127 Bcf. (2) Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was a $111 million asset as shown on CERC’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above, offset by collateral netting of $64 million . The following tables present information about CERC’s derivative instruments and hedging activities. The first four tables provide a balance sheet overview of CERC’s Derivative Assets and Liabilities as of September 30, 2015 and December 31, 2014 , while the last two tables provide a breakdown of the related income statement impacts for the three and nine months ended September 30, 2015 and 2014 . Fair Value of Derivative Instruments September 30, 2015 Total derivatives not designated as hedging instruments Balance Sheet Location Derivative Assets Fair Value Derivative Liabilities Fair Value (in millions) Natural gas derivatives (1) (2) Current Assets: Non-trading derivative assets $ 80 $ 2 Natural gas derivatives (1) (2) Other Assets: Non-trading derivative assets 39 — Natural gas derivatives (1) (2) Current Liabilities: Non-trading derivative liabilities 16 59 Natural gas derivatives (1) (2) Other Liabilities: Non-trading derivative liabilities 3 24 Total $ 138 $ 85 (1) The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 776 billion cubic feet (Bcf) or a net 77 Bcf long position. Of the net long position, basis swaps constitute 128 Bcf. (2) Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was a $100 million asset as shown on CERC’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $47 million .
Income Statement Impact of Derivative Activity Table	Realized and unrealized gains and losses on derivatives are recognized in the Condensed Statements of Consolidated Income as revenue for retail sales derivative contracts and as natural gas expense for financial natural gas derivatives and non-retail related physical natural gas derivatives. Income Statement Impact of Derivative Activity Three Months Ended September 30, Total derivatives not designated as hedging instruments Income Statement Location 2015 2014 (in millions) Natural gas derivatives Gains (Losses) in Revenue $ 39 $ 22 Natural gas derivatives (1) Gains (Losses) in Expense: Natural Gas (30 ) (4 ) Total $ 9 $ 18 (1) The Gains (Losses) in Expense: Natural Gas includes $-0- during each of the three months ended September 30, 2015 and 2014 , related to physical forwards purchased from Enable. Income Statement Impact of Derivative Activity Nine Months Ended September 30, Total derivatives not designated as hedging instruments Income Statement Location 2015 2014 (in millions) Natural gas derivatives Gains (Losses) in Revenue $ 88 $ (74 ) Natural gas derivatives (1) Gains (Losses) in Expense: Natural Gas (72 ) 110 Total $ 16 $ 36 (1) The Gains (Losses) in Expense: Natural Gas includes $-0- and $2 million during the nine months ended September 30, 2015 and 2014 , respectively, related to physical forwards purchased from Enable.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	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 September 30, 2015 and December 31, 2014 , 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 September 30, 2015 (in millions) Assets Corporate equities $ 2 $ — $ — $ — $ 2 Investments, including money market funds (2) 11 — — — 11 Natural gas derivatives 5 111 22 (21 ) 117 Total assets $ 18 $ 111 $ 22 $ (21 ) $ 130 Liabilities Natural gas derivatives $ 14 $ 63 $ 8 $ (68 ) $ 17 Total liabilities $ 14 $ 63 $ 8 $ (68 ) $ 17 (1) Amounts represent the impact of legally enforceable master netting arrangements that allow CERC to settle positive and negative positions and also include cash collateral of $47 million posted with the same counterparties. (2) Amounts are included in Prepaid Expenses and Other Current Assets in the Condensed Consolidated Balance Sheets. 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, 2014 (in millions) Assets Corporate equities $ 2 $ — $ — $ — $ 2 Investments, including money market funds (2) 11 — — — 11 Natural gas derivatives 7 122 20 (18 ) 131 Total assets $ 20 $ 122 $ 20 $ (18 ) $ 144 Liabilities Natural gas derivatives $ 22 $ 77 $ 3 $ (82 ) $ 20 Total liabilities $ 22 $ 77 $ 3 $ (82 ) $ 20 (1) Amounts represent the impact of legally enforceable master netting arrangements that allow CERC to settle positive and negative positions and also include cash collateral of $64 million posted with the same counterparties. (2) Amounts are included in Prepaid Expenses and Other Current Assets in the Condensed Consolidated Balance Sheets.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The following table presents additional information about assets or liabilities, including derivatives that are measured at fair value on a recurring basis for which 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 September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Beginning balance $ 10 $ 4 $ 17 $ 3 Total gains 5 6 5 6 Total settlements (2 ) (1 ) (8 ) 1 Transfers into Level 3 1 — 1 (1 ) Transfers out of Level 3 — — (1 ) — Ending balance (1) $ 14 $ 9 $ 14 $ 9 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 $ 6 $ 6 $ 7 $ 7 (1) CERC did not have significant Level 3 purchases or sales during either of the three or nine months ended September 30, 2015 or 2014 .
Fair Value, by Balance Sheet Grouping [Table Text Block]	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 or Level 2 in the fair value hierarchy. September 30, 2015 December 31, 2014 Carrying Fair Carrying Amount Fair Value (in millions) Financial assets: Notes receivable from unconsolidated affiliates $ 363 $ 362 $ 363 $ 362 Financial liabilities: Long-term debt $ 2,242 $ 2,460 $ 2,469 $ 2,772

Unconsolidated Affiliates (Tabl

Unconsolidated Affiliates (Tables)	9 Months Ended
	Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments [Table Text Block]	Investment in Unconsolidated Affiliates: September 30, December 31, 2014 (in millions) Enable $ 3,604 $ 4,520 SESH (1) — 1 Total $ 3,604 $ 4,521 (1) CERC disposed of its remaining interest in SESH on June 30, 2015. Equity in Earnings (Losses) of Unconsolidated Affiliates, net: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Enable $ (794 ) $ 79 $ (699 ) $ 236 SESH (1) — — — 5 Total $ (794 ) $ 79 $ (699 ) $ 241 (1) CERC disposed of its remaining interest in SESH on June 30, 2015. Summarized unaudited consolidated income information for Enable is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Operating revenues $ 646 $ 804 $ 1,852 $ 2,632 Cost of sales, excluding depreciation and amortization 287 439 856 1,550 Impairment of goodwill and other long-lived assets 1,105 1 1,105 1 Operating income (loss) (975 ) 151 (778 ) 452 Net income (loss) attributable to Enable (985 ) 139 (817 ) 408 Reconciliation of Equity in Earnings (Losses), net: CERC’s interest $ (546 ) $ 76 $ (453 ) $ 230 Basis difference accretion 2 3 4 6 Impairment of CERC’s equity method investment in Enable (250 ) — (250 ) — CERC’s equity in earnings (losses), net (1) $ (794 ) $ 79 $ (699 ) $ 236 (1) These amounts include CERC’s share of Enable’s impairment of goodwill and long-lived assets and the impairment of CERC’s equity method investment in Enable totaling $862 million during the three and nine months ended September 30, 2015. This impairment is offset by $68 million and $163 million of earnings for the three and nine months ended September 30, 2015, respectively. Summarized unaudited consolidated balance sheet information for Enable is as follows: September 30, December 31, 2014 (in millions) Current assets $ 427 $ 438 Non-current assets 10,774 11,399 Current liabilities 804 671 Non-current liabilities 2,786 2,343 Non-controlling interest 25 31 Enable partners’ capital 7,586 8,792 Reconciliation of Investment in Enable: CERC’s ownership interest in Enable partners’ capital $ 4,200 $ 4,869 CERC’s existing basis difference (346 ) (349 ) Impairment of CERC’s equity method investment in Enable (250 ) — CERC’s investment in Enable $ 3,604 $ 4,520 Distributions Received from Unconsolidated Affiliates: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Enable $ 74 $ 70 $ 219 $ 227 SESH (1) — 1 — 8 Total $ 74 $ 71 $ 219 $ 235 (1) CERC disposed of its remaining interest in SESH on June 30, 2015.

Goodwill Goodwill (Tables)

Goodwill Goodwill (Tables)	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill [Table Text Block]	Goodwill by reportable business segment as of both September 30, 2015 and December 31, 2014 is as follows: (in millions) Natural Gas Distribution $ 746 Energy Services 83 Other Operations 11 Total $ 840

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Schedule of Related Party Transactions [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Corporate service charges $ 29 $ 34 $ 88 $ 93

Short-term Borrowings and Lon27

Short-term Borrowings and Long-term Debt (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Schedule of Line of Credit Facilities [Table Text Block]	Revolving Credit Facility. As of September 30, 2015 and December 31, 2014 , CERC had the following revolving credit facility and utilization of such facility: September 30, 2015 December 31, 2014 Size of Loans Letters Commercial Loans Letters Commercial (in millions) $ 600 $ — $ 2 $ 109 $ — $ — $ 341

Reportable Business Segments (T

Reportable Business Segments (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	inancial data for business segments is as follows: For the Three Months Ended September 30, 2015 Revenues from Inter-segment Operating (in millions) Natural Gas Distribution $ 353 $ 6 $ 11 Energy Services 446 6 7 Midstream Investments (1) — — — Other Operations — — — Reconciling Eliminations — (12 ) — Consolidated $ 799 $ — $ 18 For the Three Months Ended September 30, 2014 Revenues from Inter-segment Operating (in millions) Natural Gas Distribution $ 375 $ 7 $ (8 ) Energy Services 589 15 6 Midstream Investments (1) — — — Other Operations — — (1 ) Reconciling Eliminations — (22 ) — Consolidated $ 964 $ — $ (3 ) For the Nine Months Ended September 30, 2015 Revenues from External Customers Inter-segment Revenues Operating Income Total Assets as of September 30, 2015 (in millions) Natural Gas Distribution $ 1,958 $ 21 $ 176 $ 5,360 Energy Services 1,482 28 29 852 Midstream Investments (1) — — — 3,604 Other Operations — — — 759 Reconciling Eliminations — (49 ) — (752 ) Consolidated $ 3,440 $ — $ 205 $ 9,823 For the Nine Months Ended September 30, 2014 Revenues from Inter-segment Operating Total Assets as of December 31, 2014 (in millions) Natural Gas Distribution $ 2,379 $ 22 $ 184 $ 5,464 Energy Services 2,298 66 43 978 Midstream Investments (1) — — — 4,521 Other Operations 1 — (3 ) 1,046 Reconciling Eliminations — (88 ) — (964 ) Consolidated $ 4,678 $ — $ 224 $ 11,045
Midstream Investments [Table Text Block]	Midstream Investments’ equity earnings (losses) are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions) Enable (1) $ (794 ) $ 79 $ (699 ) $ 236 SESH — — — 5 Total $ (794 ) $ 79 $ (699 ) $ 241 (1) These amounts include CERC’s share of Enable’s impairment of goodwill and long-lived assets and the impairment of CERC’s equity method investment in Enable totaling $862 million during the three and nine months ended September 30, 2015. This impairment is offset by $68 million and $163 million of earnings for the three and nine months ended September 30, 2015, respectively. Midstream Investments’ total assets are as follows: September 30, December 31, 2014 (in millions) Enable $ 3,604 $ 4,520 SESH — 1 Total $ 3,604 $ 4,521

Background and Basis of Prese29

Background and Basis of Presentation (Details)	Sep. 30, 2015
Enable Midstream Partners [Member]
Equity Method Investment, Ownership Percentage	55.40%

New Accounting Pronouncements (

New Accounting Pronouncements (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Other Noncurrent Assets [Member]
Unamortized Debt Issuance Expense	$ 16	$ 18

Employee Benefit Plans Employ31

Employee Benefit Plans Employee Benefit Plans (Details) - Other Postretirement Benefit Plans, Defined Benefit [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 1	$ 1	$ 1
Interest cost on accumulated benefit obligation	2	1	4	4
Expected return on plan assets	(1)	(1)	(1)	(1)
Amortization of loss	0	1	1	1
Net periodic cost	2	$ 2	5	$ 5
Contribution expected in 2015			7
Contribution made in period	$ 1		$ 4

Derivative Instruments Deriva32

Derivative Instruments Derivatives and Hedging (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Term of normal weather used as the basis for weather hedges (in years)			10 years
Weather Hedge Swaps [Member] | Sales [Member]
Gains (Losses) Recognized Related to Weather Hedges	$ 0	$ 0	$ (4)	$ (7)
Natural Gas Distribution | 2014To2015 [Member]
Weather Hedge, Bilateral Cap Amount			16
Natural Gas Distribution | 2013To2014 [Member]
Weather Hedge, Bilateral Cap Amount			$ 16

Derivative Instruments Deriva33

Derivative Instruments Derivative Instruments (Details) $ in Millions		3 Months Ended				9 Months Ended				12 Months Ended
		Sep. 30, 2015USD ($)		Sep. 30, 2014USD ($)		Sep. 30, 2015USD ($)Bcf		Sep. 30, 2014USD ($)		Dec. 31, 2014USD ($)Bcf
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments, Assets, Physical Forwards Purchased		$ 138				$ 138				$ 149
Derivative Liability, Fair Value, Gross Liability		85				85				102
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		9		$ 18		16		$ 36
Derivative, Fair Value, Net [Abstract]
Total fair value of the derivative instruments that contain credit risk contingency features that are in a net liability position		3				3				2
Collateral Already Posted, Aggregate Fair Value		0				0				0
Credit Risk Contingent Feature assets		3				$ 3				$ 2
Energy Related Derivative [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative, Nonmonetary Notional Amount, Volume | Bcf						776				804
Gross Amounts Recognized (1)	[1]	53				$ 53				$ 47
Derivative, Fair Value, Offsets, Net		47				47				64
Derivative Assets (Liabilities), at Fair Value, Net	[2]	100				100				111
collateral Netting		47				47				64
Energy Related Derivative [Member] | Current Assets [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	96				96				115
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset		(18)				(18)				(16)
Derivative Asset	[2]	78				78				99
Energy Related Derivative [Member] | Other Noncurrent Assets [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	[1]	42				42				34
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset		(3)				(3)				(2)
Derivative Asset	[2]	39				39				32
Energy Related Derivative [Member] | Current Liabilities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	(61)				(61)				(84)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset		49				49				65
Derivative Liability	[2]	(12)				(12)				(19)
Energy Related Derivative [Member] | Other Noncurrent Liabilities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	[1]	(24)				(24)				(18)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset		19				19				17
Derivative Liability	[2]	(5)				(5)				(1)
Energy Related Derivative [Member] | Gains (Losses) in Revenue
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		39		22		88		(74)
Energy Related Derivative [Member] | Gains (Losses) in Expense: Natural Gas [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		(30)	[3]	(4)	[3]	(72)	[4]	110	[4]
Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Current Assets [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments, Assets, Physical Forwards Purchased		80	[5],[6]			80	[5],[6]			101	[7],[8]
Derivative Liability, Fair Value, Gross Liability		2	[5],[6]			2	[5],[6]			1	[7],[8]
Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other Noncurrent Assets [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments, Assets, Physical Forwards Purchased		39	[5],[6]			39	[5],[6]			32	[7],[8]
Derivative Liability, Fair Value, Gross Liability		0	[5],[6]			0	[5],[6]			0	[7],[8]
Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Current Liabilities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments, Assets, Physical Forwards Purchased		16	[5],[6]			16	[5],[6]			14	[7],[8]
Derivative Liability, Fair Value, Gross Liability		59	[5],[6]			59	[5],[6]			83	[7],[8]
Not Designated as Hedging Instrument [Member] | Energy Related Derivative [Member] | Other Noncurrent Liabilities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments, Assets, Physical Forwards Purchased		3	[5],[6]			3	[5],[6]			2	[7],[8]
Derivative Liability, Fair Value, Gross Liability		24	[5],[6]			$ 24	[5],[6]			$ 18	[7],[8]
Long [Member] | Energy Related Derivative [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative, Nonmonetary Notional Amount, Volume | Bcf						77				60
Swap [Member] | Long [Member] | Energy Related Derivative [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative, Nonmonetary Notional Amount, Volume | Bcf						128				127
Enable Midstream Partners [Member] | Forward Contracts [Member] | Energy Related Derivative [Member] | Gains (Losses) in Expense: Natural Gas [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		$ 0		$ 0		$ 0		$ 2
[1]	Gross amounts recognized include some derivative assets and liabilities that are not subject to master netting arrangements.
[2]	The derivative assets and liabilities on the Condensed Consolidated Balance Sheets exclude accounts receivable or accounts payable that, should they exist, could be used as offsets to these balances in the event of a default.
[3]	The Gains (Losses) in Expense: Natural Gas includes $-0- during each of the three months ended September 30, 2015 and 2014, related to physical forwards purchased from Enable.
[4]	The Gains (Losses) in Expense: Natural Gas includes $-0- and $2 million during the nine months ended September 30, 2015 and 2014, respectively, related to physical forwards purchased from Enable.
[5]	Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was a $100 million asset as shown on CERC’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above offset by collateral netting of $47 million.
[6]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 776 billion cubic feet (Bcf) or a net 77 Bcf long position. Of the net long position, basis swaps constitute 128 Bcf.
[7]	Natural gas contracts are presented on a net basis in the Condensed Consolidated Balance Sheets. Natural gas contracts are subject to master netting arrangements. This netting applies to all undisputed amounts due or past due and causes derivative assets (liabilities) to be ultimately presented net in a liability (asset) account within the Condensed Consolidated Balance Sheets. The net of total non-trading derivative assets and liabilities was a $111 million asset as shown on CERC’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above, offset by collateral netting of $64 million.
[8]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 804 Bcf or a net 60 Bcf long position. Of the net long position, basis swaps constitute 127 Bcf.

Fair Value Measurements (Detail

Fair Value Measurements (Details)		3 Months Ended				9 Months Ended				12 Months Ended
		Sep. 30, 2015USD ($)		Sep. 30, 2014USD ($)		Sep. 30, 2015USD ($)		Sep. 30, 2014USD ($)		Dec. 31, 2014USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount		$ 0				$ 0
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount		0				0
Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount		0				0
Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount		0				0
Equity Method Investments		3,604,000,000				3,604,000,000				$ 4,521,000,000
ASSETS
Natural gas derivatives, netting adjustment		(21,000,000)	[1]			(21,000,000)	[1]			(18,000,000)	[2]
Total assets		130,000,000				130,000,000				144,000,000
Liabilities [Abstract]
Natural gas derivatives, netting adjustment		(68,000,000)	[1]			(68,000,000)	[1]			(82,000,000)	[2]
Liabilities, Fair Value Disclosure, Recurring		17,000,000				17,000,000				20,000,000
Cash collateral posted with counterparties		47,000,000				47,000,000				64,000,000
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance		10,000,000		$ 4,000,000		17,000,000		$ 3,000,000		3,000,000
Total gains		5,000,000		6,000,000		5,000,000		6,000,000
Total settlements		(2,000,000)		(1,000,000)		(8,000,000)		1,000,000
Transfers into Level 3		1,000,000		0		1,000,000		(1,000,000)
Transfers out of Level 3		0		0		(1,000,000)		0
Ending balance (1)		14,000,000	[3]	9,000,000	[3]	14,000,000	[3]	9,000,000	[3]	17,000,000
The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date		6,000,000		6,000,000		7,000,000		7,000,000
Carrying Amount [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation Calculation Roll Forward
Notes receivable from unconsolidated affiliates		363,000,000				363,000,000				363,000,000
Long-term debt		2,242,000,000				2,242,000,000				2,469,000,000
Fair Value [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation Calculation Roll Forward
Notes receivable from unconsolidated affiliates		362,000,000				362,000,000				362,000,000
Long-term debt		2,460,000,000				2,460,000,000				2,772,000,000
Fair Value, Inputs, Level 1 [Member]
ASSETS
Total assets		18,000,000				18,000,000				20,000,000
Liabilities [Abstract]
Liabilities, Fair Value Disclosure, Recurring		14,000,000				14,000,000				22,000,000
Fair Value, Inputs, Level 2 [Member]
ASSETS
Total assets		111,000,000				111,000,000				122,000,000
Liabilities [Abstract]
Liabilities, Fair Value Disclosure, Recurring		63,000,000				63,000,000				77,000,000
Fair Value, Inputs, Level 3 [Member]
ASSETS
Total assets		22,000,000				22,000,000				20,000,000
Liabilities [Abstract]
Liabilities, Fair Value Disclosure, Recurring		8,000,000				$ 8,000,000				3,000,000
Forward Contracts [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Price Per MMBtu						1.17
Forward Contracts [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Price Per MMBtu						3.78
Options Held [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assumptions, Expected Volatility Rate						0.00%
Options Held [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assumptions, Expected Volatility Rate						76.00%
Fair Value, Measurements, Recurring [Member]
ASSETS
Corporate equities		2,000,000				$ 2,000,000				2,000,000
Investments, including money market funds	[4]	11,000,000				11,000,000				11,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
ASSETS
Corporate equities		2,000,000				2,000,000				2,000,000
Investments, including money market funds	[4]	11,000,000				11,000,000				11,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
ASSETS
Corporate equities		0				0				0
Investments, including money market funds	[4]	0				0				0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
ASSETS
Corporate equities		0				0				0
Investments, including money market funds	[4]	0				0				0
Fair Value, Measurements, Recurring [Member] | Energy Related Derivative [Member]
ASSETS
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset		(21,000,000)	[1]			(21,000,000)	[1]			(18,000,000)	[2]
Derivative Asset		117,000,000				117,000,000				131,000,000
Liabilities [Abstract]
Derivative Liability		17,000,000				17,000,000				20,000,000
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset		(68,000,000)	[1]			(68,000,000)	[1]			(82,000,000)	[2]
Fair Value, Measurements, Recurring [Member] | Energy Related Derivative [Member] | Fair Value, Inputs, Level 1 [Member]
ASSETS
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		5,000,000				5,000,000				7,000,000
Liabilities [Abstract]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		14,000,000				14,000,000				22,000,000
Fair Value, Measurements, Recurring [Member] | Energy Related Derivative [Member] | Fair Value, Inputs, Level 2 [Member]
ASSETS
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		111,000,000				111,000,000				122,000,000
Liabilities [Abstract]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		63,000,000				63,000,000				77,000,000
Fair Value, Measurements, Recurring [Member] | Energy Related Derivative [Member] | Fair Value, Inputs, Level 3 [Member]
ASSETS
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		22,000,000				22,000,000				20,000,000
Liabilities [Abstract]
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		8,000,000				8,000,000				3,000,000
Enable Midstream Partners [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Method Investment, Other than Temporary Impairment		250,000,000		$ 0		250,000,000		$ 0		0
Equity Method Investments		$ 3,604,000,000				$ 3,604,000,000				$ 4,520,000,000
[1]	Amounts represent the impact of legally enforceable master netting arrangements that allow CERC to settle positive and negative positions and also include cash collateral of $47 million posted with the same counterparties.
[2]	Amounts represent the impact of legally enforceable master netting arrangements that allow CERC to settle positive and negative positions and also include cash collateral of $64 million posted with the same counterparties.
[3]	CERC did not have significant Level 3 purchases or sales during either of the three or nine months ended September 30, 2015 or 2014.
[4]	Amounts are included in Prepaid Expenses and Other Current Assets in the Condensed Consolidated Balance Sheets.

Unconsolidated Affiliates Descr

Unconsolidated Affiliates Description (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Jun. 30, 2015	May. 30, 2014	Mar. 31, 2014
Accounts and notes receivable–affiliated companies		$ 75		$ 75		$ 18
Equity in earnings (losses) of unconsolidated affiliates, net		(794)	$ 79	(699)	$ 241
Investment in unconsolidated affiliates		$ 3,604		$ 3,604		4,521
Enable Midstream Partners [Member]
Equity Method Investment, Ownership Percentage		55.40%		55.40%
Equity in earnings (losses) of unconsolidated affiliates, net		$ (794)	79	$ (699)	236
Equity Method Investment, Other than Temporary Impairment		250	0	250	0	0
Asset Impairment Charges		612
Investment in unconsolidated affiliates		3,604		3,604		4,520
Enable Midstream Partners [Member] | CERC Corp [Member]
Impairment Charges		862		862
Southeast Supply Header LLC [Member]
Equity Method Investment, Ownership Percentage									25.05%
Equity Method Investment, Contributed Ownership Percentage							0.10%	24.95%
Equity in earnings (losses) of unconsolidated affiliates, net	[1]	0	0	0	5
Investment in unconsolidated affiliates	[1]	$ 0		$ 0		1
Subordinated Units [Member] | Enable Midstream Partners [Member]
Equity Method Investment, Ownership, Shares		139,704,916		139,704,916
Common Stock [Member] | Enable Midstream Partners [Member]
Equity Method Investment, Ownership, Shares		94,151,707		94,151,707
Enable Guaranteed Senior Notes [Member]
Guarantee of Affiliate Senior Notes		$ 1,100		$ 1,100
Enable Midstream Partners [Member]
Due from Affiliate, Noncurrent		363		363
Interest Income, Related Party		2	2	6	6
Accounts and notes receivable–affiliated companies		2		2		4
Transitional Service [Member] | Enable Midstream Partners [Member]
Reimbursement Revenue		3	36	10	118
Accounts Receivable, Related Parties		4		4		28
Natural Gas Expenses [Member] | Enable Midstream Partners [Member]
Affiliate Costs		23	$ 24	87	$ 99
Accounts Payable, Related Parties, Current		8		8		$ 23
Enable Midstream Partners [Member] | Enable Guaranteed Senior Notes [Member]
Guarantee of Affiliate Senior Notes		$ 1,100		$ 1,100
Indebtedness to CERC Corp. [Member] | Enable Midstream Partners [Member]
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum				2.10%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum				2.45%
General Partner [Member] | CERC Corp [Member]
Management Rights Ownership Percentage				50.00%
Incentive Distribution Right				40.00%
General Partner [Member] | OGE [Member]
Management Rights Ownership Percentage				50.00%
Incentive Distribution Right				60.00%
[1]	CERC disposed of its remaining interest in SESH on June 30, 2015.

Unconsolidated Affiliates Finan

Unconsolidated Affiliates Financial Data(Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended		12 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Investment in unconsolidated affiliates		$ 3,604		$ 3,604		$ 4,521
Equity in earnings (losses) of unconsolidated affiliates, net		(794)	$ 79	(699)	$ 241
Equity Method Investment, Summarized Financial Information, Assets [Abstract]
Investment in unconsolidated affiliates		3,604		3,604		4,521
Proceeds from Equity Method Investment, Dividends or Distributions		74	71	219	235
Enable Midstream Partners [Member]
Investment in unconsolidated affiliates		3,604		3,604		4,520
Equity in earnings (losses) of unconsolidated affiliates, net		(794)	79	(699)	236
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Operating revenues		646	804	1,852	2,632
Cost of sales, excluding depreciation and amortization		287	439	856	1,550
Impairment of goodwill and other long-lived assets		1,105	1	1,105	1
Operating income (loss)		(975)	151	(778)	452
Net income (loss) attributable to Enable		(985)	139	(817)	408
CERC’s interest		(546)	76	(453)	230
Basis difference accretion		2	3	4	6
Impairment of CERC’s equity method investment in Enable		(250)	0	(250)	0	0
CERC’s equity in earnings (losses), net (1)	[1]	(794)	79	(699)	236
Income (Loss) From Equity Method Investment, Excluding Impairment Charge		68		163
Equity Method Investment, Summarized Financial Information, Assets [Abstract]
Current assets		427		427		438
Non-current assets		10,774		10,774		11,399
Current liabilities		804		804		671
Non-current liabilities		2,786		2,786		2,343
Non-controlling interest		25		25		31
Enable partners’ capital		7,586		7,586		8,792
CERC’s ownership interest in Enable partners’ capital		4,200		4,200		4,869
Equity Method Investment, Basis Difference		(346)		(346)		(349)
Impairment of CERC’s equity method investment in Enable		(250)	0	(250)	0	0
Investment in unconsolidated affiliates		3,604		3,604		4,520
Proceeds from Equity Method Investment, Dividends or Distributions		74	70	219	227
Southeast Supply Header LLC [Member]
Investment in unconsolidated affiliates	[2]	0		0		1
Equity in earnings (losses) of unconsolidated affiliates, net	[2]	0	0	0	5
Equity Method Investment, Summarized Financial Information, Assets [Abstract]
Investment in unconsolidated affiliates	[2]	0		0		$ 1
Proceeds from Equity Method Investment, Dividends or Distributions	[2]	0	$ 1	0	$ 8
CERC Corp [Member] | Enable Midstream Partners [Member]
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Impairment Charges		$ 862		$ 862
[1]	$862 million during the three and nine months ended September 30, 2015. This impairment is offset by $68 million and $163 million of earnings for the three and nine months ended September 30, 2015, respectively.
[2]	CERC disposed of its remaining interest in SESH on June 30, 2015.

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Goodwill [Line Items]
Goodwill	$ 840	$ 840
Natural Gas Distribution
Goodwill [Line Items]
Goodwill	746	746
Energy Services
Goodwill [Line Items]
Goodwill	83	83
Other Operations
Goodwill [Line Items]
Goodwill	$ 11	$ 11

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Money Pool Borrowings	$ 0		$ 0		$ 188
Corporate service charges, related party	$ 29	$ 34	$ 88	$ 93

Short-term Borrowings and Lon39

Short-term Borrowings and Long-term Debt (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Short-term Debt	$ 49	$ 53
Line of Credit Facility, Maximum Borrowing Capacity	600	600
Product Financing Arrangement [Member]
Short-term Debt	49	53
Revolving Credit Facility [Member]
Loans Outstanding	$ 0	0
Percentage on limitation of debt to total capitalization under covenant	65.00%
Letter of Credit [Member]
Loans Outstanding	$ 2	0
Commercial Paper [Member]
Loans Outstanding	$ 109	$ 341
London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member]
Debt Instrument, Basis Spread on Variable Rate	1.50%

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015USD ($)
Natural Gas Supply Commitments [Member]
Recorded Unconditional Purchase Obligation Payment Schedule [Abstract]
2,015	$ 159
2,016	489
2,017	466
2,018	413
2,019	224
After 2,019	$ 128
Gas Market Manipulation Cases [Member]
Recorded Unconditional Purchase Obligation Payment Schedule [Abstract]
Loss Contingency Pending Natural Gas Measurement Lawsuits Number	1
Minnesota Service Territory [Member]
Recorded Unconditional Purchase Obligation Payment Schedule [Abstract]
Site Contingency Remaining Minnesota Sites	7
Site Contingency Sites Without Liability	2
Site Contingency Completed Remediation	2
LegalEnvironmentalAndOtherRegulatoryMattersLegalMattersGasMarketManipulationCasesAbstract
Accrual for Environmental Loss Contingencies	$ 7
Site Contingency Sites With Liability	5
Minnesota Service Territory [Member] | Maximum [Member]
LegalEnvironmentalAndOtherRegulatoryMattersLegalMattersGasMarketManipulationCasesAbstract
Site Contingency, Loss Exposure Not Accrued, Low Estimate	$ 28
Site Contingency, Years to Resolve Contingency	50 years
Minnesota Service Territory [Member] | Minimum [Member]
LegalEnvironmentalAndOtherRegulatoryMattersLegalMattersGasMarketManipulationCasesAbstract
Site Contingency, Loss Exposure Not Accrued, Low Estimate	$ 4
Site Contingency, Years to Resolve Contingency	30 years
GenOn Demand Charges Transportation Contracts [Member]
LegalEnvironmentalAndOtherRegulatoryMattersLegalMattersGasMarketManipulationCasesAbstract
Guarantee of Affiliate Senior Notes	$ 31
Enable Guaranteed Senior Notes [Member]
LegalEnvironmentalAndOtherRegulatoryMattersLegalMattersGasMarketManipulationCasesAbstract
Guarantee of Affiliate Senior Notes	$ 1,100

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Effective Income Tax Rate	37.00%	35.00%	37.00%	38.00%
Income Tax Expense (Benefit)	$ (2)

Reportable Business Segments (D

Reportable Business Segments (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues		$ 799	$ 964	$ 3,440	$ 4,678
Operating Income (Loss)		18	(3)	205	224
Assets		9,823		9,823		$ 11,045
Equity in earnings (losses) of unconsolidated affiliates, net		(794)	79	(699)	241
Investment in unconsolidated affiliates		3,604		3,604		4,521
Natural Gas Distribution
Segment Reporting Information [Line Items]
Revenues		353	375	1,958	2,379
Operating Income (Loss)		11	(8)	176	184
Energy Services
Segment Reporting Information [Line Items]
Revenues		446	589	1,482	2,298
Operating Income (Loss)		7	6	29	43
Midstream Investments (1)
Segment Reporting Information [Line Items]
Revenues	[1]	0	0	0	0
Operating Income (Loss)	[1]	0	0	0	0
Other Operations
Segment Reporting Information [Line Items]
Revenues		0	0	0	1
Operating Income (Loss)		0	(1)	0	(3)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues		(12)	(22)	(49)	(88)
Assets		(752)		(752)		(964)
Intersegment Eliminations | Natural Gas Distribution
Segment Reporting Information [Line Items]
Revenues		(6)	(7)	(21)	(22)
Intersegment Eliminations | Energy Services
Segment Reporting Information [Line Items]
Revenues		(6)	(15)	(28)	(66)
Intersegment Eliminations | Midstream Investments (1)
Segment Reporting Information [Line Items]
Revenues	[1]	0	0	0	0
Intersegment Eliminations | Other Operations
Segment Reporting Information [Line Items]
Revenues		0	0	0	0
Operating Segments [Member] | Natural Gas Distribution
Segment Reporting Information [Line Items]
Assets		5,360		5,360		5,464
Operating Segments [Member] | Energy Services
Segment Reporting Information [Line Items]
Assets		852		852		978
Operating Segments [Member] | Midstream Investments (1)
Segment Reporting Information [Line Items]
Assets	[1]	3,604		3,604		4,521
Operating Segments [Member] | Other Operations
Segment Reporting Information [Line Items]
Assets		759		759		1,046
Southeast Supply Header LLC [Member]
Segment Reporting Information [Line Items]
Equity in earnings (losses) of unconsolidated affiliates, net	[2]	0	0	0	5
Investment in unconsolidated affiliates	[2]	0		0		1
Southeast Supply Header LLC [Member] | Midstream Investments (1)
Segment Reporting Information [Line Items]
Equity in earnings (losses) of unconsolidated affiliates, net		0	0	0	5
Investment in unconsolidated affiliates		0		0		1
Enable Midstream Partners [Member]
Segment Reporting Information [Line Items]
Equity in earnings (losses) of unconsolidated affiliates, net		(794)	79	(699)	236
Investment in unconsolidated affiliates		3,604		3,604		4,520
Income (Loss) From Equity Method Investment, Excluding Impairment Charge		68		163
Enable Midstream Partners [Member] | Midstream Investments (1)
Segment Reporting Information [Line Items]
Equity in earnings (losses) of unconsolidated affiliates, net	[3]	(794)	$ 79	(699)	$ 236
Investment in unconsolidated affiliates		3,604		3,604		$ 4,520
Enable Midstream Partners [Member] | CERC Corp [Member]
Segment Reporting Information [Line Items]
Impairment Charges		$ 862		$ 862
[1]	Midstream Investments’ equity earnings (losses) are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (in millions)Enable (1) $(794) $79 $(699) $236SESH — — — 5 Total $(794) $79 $(699) $241(1)These amounts include CERC’s share of Enable’s impairment of goodwill and long-lived assets and the impairment of CERC’s equity method investment in Enable totaling $862 million during the three and nine months ended September 30, 2015. This impairment is offset by $68 million and $163 million of earnings for the three and nine months ended September 30, 2015, respectively.Midstream Investments’ total assets are as follows: September 30, 2015 December 31, 2014 (in millions)Enable $3,604 $4,520SESH — 1 Total $3,604 $4,521
[2]	CERC disposed of its remaining interest in SESH on June 30, 2015.
[3]	These amounts include CERC’s share of Enable’s impairment of goodwill and long-lived assets and the impairment of CERC’s equity method investment in Enable totaling $862 million during the three and nine months ended September 30, 2015. This impairment is offset by $68 million and $163 million of earnings for the three and nine months ended September 30, 2015, respectively.

Other Current Assets and Liab43

Other Current Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Margin Deposits	$ 16	$ 19
Under Recovered Gas Costs	8	45
Over Recovered Gas Costs	$ 78	$ 37

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	Oct. 22, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Subsequent Event [Line Items]
Proceeds from Equity Method Investment, Dividends or Distributions		$ 74	$ 71	$ 219	$ 235
Enable Midstream Partners [Member]
Subsequent Event [Line Items]
Proceeds from Equity Method Investment, Dividends or Distributions		$ 74	$ 70	$ 219	$ 227
Enable Midstream Partners [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends Payable, Date Declared	Oct. 22, 2015
Common Stock, Dividends, Per Share, Declared	$ 0.318
Proceeds from Equity Method Investment, Dividends or Distributions	$ 74