CenterPoint Energy (CNP) 10-Q 10 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Supplementa

Document and Entity Supplemental Information Document - USD ($)	6 Months Ended
	Jun. 30, 2015	Jul. 31, 2015	Jun. 30, 2014
Entity Information [Line Items]
Entity Registrant Name	CENTERPOINT ENERGY INC.
Entity Central Index Key	1,130,310
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		430,261,710
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 10,907,234,073

Condensed Statements of Consoli

Condensed Statements of Consolidated Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Revenues	$ 1,532	$ 1,884	$ 3,965	$ 5,047
Expenses:
Natural gas	529	880	1,883	2,923
Operation and maintenance	488	469	986	948
Depreciation and amortization	239	256	456	491
Taxes other than income taxes	90	93	198	204
Total	1,346	1,698	3,523	4,566
Operating Income	186	186	442	481
Other Income (Expense):
Gain on marketable securities	79	72	62	42
Loss on indexed debt securities	(91)	(50)	(67)	(7)
Interest and other finance charges	(89)	(89)	(178)	(173)
Interest on transition and system restoration bonds	(27)	(30)	(55)	(60)
Equity in earnings of unconsolidated affiliates, net	43	71	95	162
Other, net	13	9	24	18
Total	(72)	(17)	(119)	(18)
Income Before Income Taxes	114	169	323	463
Income tax expense	37	62	115	171
Net Income	$ 77	$ 107	$ 208	$ 292
Basic Earnings Per Share	$ 0.18	$ 0.25	$ 0.48	$ 0.68
Diluted Earnings Per Share	0.18	0.25	0.48	0.68
Dividends Declared Per Share	$ 0.2475	$ 0.2375	$ 0.4950	$ 0.4750
Weighted Average Shares Outstanding, Basic	430,235,000	429,773,000	430,096,000	429,470,000
Weighted Average Shares Outstanding, Diluted	431,733,000	431,409,000	431,594,000	431,106,000

Condensed Statements of Consol3

Condensed Statements of Consolidated Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 77	$ 107	$ 208	$ 292
Other comprehensive income:
Adjustment related to pension and other postretirement plans (net of tax of $0, $2, $2 and $3)	2	2	4	3
Total	2	2	4	3
Comprehensive income	$ 79	$ 109	$ 212	$ 295

Comprehensive Income Parentheti

Comprehensive Income Parentheticals - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income, Pension and Other Postretirement Benefit Plans, Tax	$ 0	$ 2	$ 2	$ 3

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Current Assets:
Cash and cash equivalents ($235 and $290 related to VIEs, respectively)	$ 245	$ 298
Investment in marketable securities	960	930
Accounts receivable ($71 and $58 related to VIEs, respectively), less bad debt reserve of $27 and $26, respectively	640	837
Accrued unbilled revenues	183	357
Natural gas inventory	96	211
Materials and supplies	178	168
Non-trading derivative assets	64	99
Taxes receivable	38	190
Prepaid expenses and other current assets ($34 and $47 related to VIEs, respectively)	105	178
Total current assets	2,509	3,268
Property, Plant and Equipment:
Property, plant and equipment	15,967	15,358
Less: accumulated depreciation and amortization	5,056	4,856
Property, plant and equipment, net	10,911	10,502
Other Assets:
Goodwill	840	840
Regulatory assets ($2,581 and $2,738 related to VIEs, respectively)	3,324	3,527
Notes receivable - affiliated companies	363	363
Non-trading derivative assets	33	32
Investment in unconsolidated affiliates	4,471	4,521
Other	151	147
Total other assets	9,182	9,430
Total Assets	22,602	23,200
Current Liabilities:
Short-term borrowings	24	53
Current portion of VIE transition and system restoration bonds long-term debt	381	372
Indexed debt	149	152
Current portion of other long-term debt	397	271
Indexed debt securities derivative	583	541
Accounts payable	367	716
Taxes accrued	90	161
Interest accrued	161	124
Non-trading derivative liabilities	7	19
Deferred income taxes, net	581	683
Other	385	383
Total current liabilities	3,125	3,475
Other Liabilities:
Deferred income taxes, net	4,863	4,757
Non-trading derivative liabilities	6	1
Benefit obligations	925	953
Regulatory liabilities	1,269	1,206
Other	250	251
Total other liabilities	7,313	7,168
Long-term Debt:
VIE transition and system restoration bonds	2,466	2,674
Other	5,148	5,335
Total long-term debt	$ 7,614	$ 8,009
Commitments and Contingencies (Note 13)
Shareholders’ Equity:
Common stock (430,259,857 shares and 429,795,830 shares outstanding, respectively)	$ 4	$ 4
Additional paid-in capital	4,172	4,169
Retained earnings	456	461
Accumulated other comprehensive loss	(82)	(86)
Total shareholders’ equity	4,550	4,548
Total Liabilities and Shareholders’ Equity	$ 22,602	$ 23,200

Balance Sheets Parentheticals

Balance Sheets Parentheticals - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Cash and cash equivalents	$ 245	$ 298
Bad Debt Reserve	27	26
Accounts receivable, net	640	837
Prepaid expenses and other current assets	105	178
Regulatory assets	$ 3,324	$ 3,527
Total common stock outstanding (in shares)	430,259,857	429,795,830
Variable Interest Entity, Primary Beneficiary [Member]
Cash and cash equivalents	$ 235	$ 290
Accounts receivable, net	71	58
Prepaid expenses and other current assets	34	47
Regulatory assets	$ 2,581	$ 2,738

Condensed Statements of Consol7

Condensed Statements of Consolidated Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash Flows from Operating Activities:
Net income	$ 208	$ 292
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	456	491
Amortization of deferred financing costs	14	14
Deferred income taxes	4	13
Unrealized gain on marketable securities	62	42
Loss on indexed debt securities	(67)	(7)
Write-down of natural gas inventory	2	0
Equity in earnings of unconsolidated affiliates, net of distributions	50	2
Pension contributions	(25)	(34)
Changes in other assets and liabilities:
Accounts receivable and unbilled revenues, net	367	211
Inventory	103	(10)
Taxes receivable	152	0
Accounts payable	(327)	(174)
Fuel cost recovery	86	(42)
Non-trading derivatives, net	2	(11)
Margin deposits, net	25	(2)
Interest and taxes accrued	(66)	(44)
Net regulatory assets and liabilities	78	46
Other current assets	23	17
Other current liabilities	(38)	(50)
Other assets	0	8
Other liabilities	(3)	21
Other, net	6	(1)
Net cash provided by operating activities	1,122	712
Cash Flows from Investing Activities:
Capital expenditures	(712)	(625)
Decrease (increase) in restricted cash of transition and system restoration bond companies	13	(10)
Proceeds from sale of marketable securities	0	(1)
Proceeds from sale of marketable securities	32	0
Other, net	(4)	(23)
Net cash used in investing activities	(671)	(659)
Cash Flows from Financing Activities:
Decrease in short-term borrowings, net	(29)	(1)
Proceeds (payments) of commercial paper, net	137	(77)
Proceeds from long-term debt	0	600
Payments of long-term debt	(400)	(373)
Debt issuance costs	0	(6)
Payment of common stock dividends	(213)	(204)
Other, net	1	6
Net cash used in financing activities	(504)	(55)
Net Decrease in Cash and Cash Equivalents	(53)	(2)
Cash and Cash Equivalents at Beginning of Period	298	208
Cash and Cash Equivalents at End of Period	245	206
Cash Payments:
Interest, net of capitalized interest	209	203
Income tax payments (refunds), net	(38)	140
Non-cash transactions:
Accounts payable related to capital expenditures	81	78
Exercise of SESH put to Enable	$ 1	$ 0

Background and Basis of Present

Background and Basis of Presentation	6 Months Ended
	Jun. 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, Inc. are the condensed consolidated interim financial statements and notes (Interim Condensed Financial Statements) of CenterPoint Energy, Inc. and its subsidiaries (collectively, CenterPoint Energy). The Interim Condensed Financial Statements are unaudited, omit certain financial statement disclosures and should be read with the Annual Report on Form 10-K of CenterPoint Energy for the year ended December 31, 2014 (CenterPoint Energy Form 10-K). Background. CenterPoint Energy, Inc. is a public utility holding company. CenterPoint Energy’s operating subsidiaries own and operate electric transmission and distribution facilities and natural gas distribution facilities and own interests in Enable Midstream Partners, LP (Enable) as described in Note 7 . As of June 30, 2015 , CenterPoint Energy’s indirect wholly owned subsidiaries included: • CenterPoint Energy Houston Electric, LLC (CenterPoint Houston), which engages in the electric transmission and distribution business in the Texas Gulf Coast area that includes the city of Houston; and • CenterPoint Energy Resources Corp. (CERC Corp. and, together with its subsidiaries, CERC), which owns and operates natural gas distribution systems. 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 June 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. As of June 30, 2015 , CenterPoint Energy had variable interest entities (VIEs) consisting of transition and system restoration bond companies, which it consolidates. The consolidated VIEs are wholly owned bankruptcy remote special purpose entities that were formed specifically for the purpose of securitizing transition and system restoration related property. Creditors of CenterPoint Energy have no recourse to any assets or revenues of the transition and system restoration bond companies. The bonds issued by these VIEs are payable only from and secured by transition and system restoration property, and the bondholders have no recourse to the general credit of CenterPoint Energy. Basis of Presentation. The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. CenterPoint Energy’s Interim Condensed Financial Statements reflect all normal recurring adjustments that are, in the opinion of management, necessary to present fairly the financial position, results of operations and cash flows for the respective periods. Amounts reported in CenterPoint Energy’s Condensed Statements of Consolidated Income are not necessarily indicative of amounts expected for a full-year period due to the effects of, among other things, (a) seasonal fluctuations in demand for energy and energy services, (b) changes in energy commodity prices, (c) timing of maintenance and other expenditures and (d) acquisitions and dispositions of businesses, assets and other interests. For a description of CenterPoint Energy’s reportable business segments, see Note 15 .

New Accounting Pronouncements

New Accounting Pronouncements	6 Months Ended
	Jun. 30, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	New Accounting Pronouncements In February 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis (ASU 2015-02). ASU 2015 -02 changes the analysis that reporting organizations must perform to evaluate whether they should consolidate certain legal entities, such as limited partnerships. The changes include, among others, modification of the evaluation of whether limited partnerships and similar legal entities are variable interest entities (VIEs) or voting interest entities and elimination of the presumption that a general partner should consolidate a limited partnership. ASU 2015-02 does not amend the related party guidance for situations in which power is shared between two or more entities that hold interests in a VIE. ASU 2015 -02 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2015. CenterPoint Energy will adopt ASU 2015-02 on January 1, 2016 and is currently assessing the impact, if any, that this standard will have on its financial position, results of operations, cash flows and disclosures. In April 2015, the FASB issued Accounting Standards Update No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Cost (ASU 2015-03) . ASU 2015-03 requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by ASU 2015-03. CenterPoint Energy will adopt ASU 2015-03 retrospectively on January 1, 2016, which will result in a reduction of both other long-term assets and long-term debt on its Condensed Consolidated Balance Sheets. CenterPoint Energy had debt issuance costs of $57 million and $61 million included in other long-term assets on its Condensed Consolidated Balance Sheets as of June 30, 2015 and December 31, 2014, respectively. In April 2015, the FASB issued Accounting Standards Update No. 2015-05, Intangibles-Goodwill and Other-Internal-Use Software ( Subtopic 350-40 ) (ASU 2015-05). ASU 2015-05 provides guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The guidance will not change a customer’s accounting for service contracts. ASU 2015-05 is effective for fiscal years, and interim periods within the fiscal years, beginning after December 15, 2015 and may be adopted either prospectively or retrospectively. CenterPoint Energy 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 July 2015, the FASB issued Accounting Standard Update, Revenue from Contracts with Customers (Topic 606) : Deferral of the Effective Date , which delays the effective date of ASU 2014-09 by one year. CenterPoint Energy 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. Management believes that other recently issued standards, which are not yet effective, will not have a material impact on CenterPoint Energy’s consolidated financial position, results of operations or cash flows upon adoption.

Employee Benefit Plans

Employee Benefit Plans	6 Months Ended
	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	Employee Benefit Plans CenterPoint Energy’s net periodic cost includes the following components relating to pension and postretirement benefits: Three Months Ended June 30, 2015 2014 Pension Postretirement Pension Postretirement (in millions) Service cost $ 10 $ — $ 11 $ 1 Interest cost 23 5 25 5 Expected return on plan assets (30 ) (1 ) (31 ) (2 ) Amortization of prior service cost (credit) 2 (1 ) 2 (1 ) Amortization of net loss 15 1 11 1 Amortization of transition obligation — — — 2 Net periodic cost $ 20 $ 4 $ 18 $ 6 Six Months Ended June 30, 2015 2014 Pension Benefits (1) Postretirement Benefits (1) Pension Benefits (1) Postretirement Benefits (1) (in millions) Service cost $ 20 $ 1 $ 21 $ 1 Interest cost 46 10 50 11 Expected return on plan assets (60 ) (3 ) (62 ) (4 ) Amortization of prior service cost (credit) 5 (1 ) 5 (1 ) Amortization of net loss 29 2 22 1 Amortization of transition obligation — — — 3 Settlement cost (2) 9 — — — Net periodic cost $ 49 $ 9 $ 36 $ 11 ________________ (1) Net periodic cost in these tables is before considering amounts subject to overhead allocations for capital expenditure projects or for amounts subject to deferral for regulatory purposes. (2) A one-time, non-cash settlement charge is required when lump sum distributions or other settlements of plan benefit obligations during a plan year exceed the service cost and interest cost components of net periodic cost for that year. Due to the amount of lump sum payment distributions from the non-qualified pension plan during the six months ended June 30, 2015 , CenterPoint Energy recognized a non-cash settlement charge of $9 million . This charge is an acceleration of costs that would otherwise be recognized in future periods. CenterPoint Energy will continue to recognize incremental settlement costs in subsequent quarters as additional lump sum distributions are made under the non-qualified pension plan. CenterPoint Energy’s changes in accumulated comprehensive loss related to defined benefit and postretirement plans are as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Pension and Postretirement Plans Pension and Postretirement Plans (in millions) Beginning Balance $ (83 ) $ (87 ) $ (85 ) $ (88 ) Amounts reclassified from accumulated other comprehensive loss: Prior service cost (1) — 1 — 1 Actuarial losses (1) 2 3 6 5 Total reclassifications from accumulated other comprehensive loss 2 4 6 6 Tax expense — (2 ) (2 ) (3 ) Net current period other comprehensive income 2 2 4 3 Ending Balance $ (81 ) $ (85 ) $ (81 ) $ (85 ) ________________ (1) These components are included in the computation of net periodic cost. CenterPoint Energy expects to contribute a total of approximately $66 million to its pension plans in 2015 , of which approximately $2 million and $25 million were contributed during the three and six months ended June 30, 2015 . CenterPoint Energy expects to contribute a total of approximately $17 million to its postretirement benefits plan in 2015 , of which approximately $3 million and $8 million were contributed during the three and six months ended June 30, 2015 .

Regulatory Accounting

Regulatory Accounting	6 Months Ended
	Jun. 30, 2015
Regulatory Assets and Liabilities, Other Disclosures [Abstract]
Regulatory Matters	Regulatory Accounting As of June 30, 2015 , CenterPoint Energy has not recognized an allowed equity return of $421 million because such return will be recognized as it is recovered in rates. During the three months ended June 30, 2015 and 2014 , CenterPoint Houston recognized approximately $12 million and $17 million , respectively, of the allowed equity return not previously recognized. During the six months ended June 30, 2015 and 2014 , CenterPoint Houston recognized approximately $21 million and $32 million , respectively, of the allowed equity return not previously recognized.

Derivative Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments CenterPoint Energy is exposed to various market risks. These risks arise from transactions entered into in the normal course of business. CenterPoint Energy utilizes derivative instruments such as physical forward contracts, swaps and options to mitigate the impact of changes in commodity prices and weather on its operating results and cash flows. Such derivatives are recognized in CenterPoint Energy’s Condensed Consolidated Balance Sheets at their fair value unless CenterPoint Energy elects the normal purchase and sales exemption for qualified physical transactions. A derivative may be designated as a normal purchase or sale if the intent is to physically receive or deliver the product for use or sale in the normal course of business. CenterPoint Energy has a Risk Oversight Committee composed of corporate and business segment officers that oversees commodity price, weather and credit risk activities, including CenterPoint Energy’s marketing, risk management services and hedging activities. The committee’s duties are to establish CenterPoint Energy’s commodity risk policies, allocate board-approved commercial risk limits, approve the use of new products and commodities, monitor positions and ensure compliance with CenterPoint Energy’s risk management policies, procedures and limits established by CenterPoint Energy’s board of directors. CenterPoint Energy’s policies prohibit the use of leveraged financial instruments. A leveraged financial instrument, for this purpose, is a transaction involving a derivative whose financial impact will be based on an amount other than the notional amount or volume of the instrument. (a) Non-Trading Activities Derivative Instruments. CenterPoint Energy enters into certain derivative instruments to manage physical commodity price 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. CenterPoint Energy has weather normalization or other rate mechanisms that mitigate the impact of weather on its natural gas distribution business (NGD) in Arkansas, Louisiana, Mississippi and Oklahoma. NGD in Texas and Minnesota and electric operations in Texas do not have such mechanisms. As a result, fluctuations from normal weather may have a significant positive or negative effect on NGD’s results in Texas and Minnesota and on CenterPoint Houston’s results in its service territory, although NGD’s Minnesota division implemented a full decoupling pilot in July 2015, which includes the effects of weather in the calculation. CenterPoint Energy 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. CenterPoint Energy also entered into a winter weather hedge for the CenterPoint Houston service territory, which contained a bilateral dollar cap of $8 million in both 2013–2014 and 2014–2015. The swaps are based on ten -year normal weather. During the three months ended June 30, 2015 and 2014 , CenterPoint Energy recognized gains of $1 million and losses of $-0- , respectively, related to these swaps. During the six months ended June 30, 2015 and 2014 , CenterPoint Energy recognized losses of $9 million and $8 million , respectively, related to these swaps. Weather hedge gains and losses are included in revenues in the Condensed Statements of Consolidated Income. (b) Derivative Fair Values and Income Statement Impacts The following tables present information about CenterPoint Energy’s derivative instruments and hedging activities. The first four tables provide a balance sheet overview of CenterPoint Energy’s Derivative Assets and Liabilities as of June 30, 2015 and December 31, 2014 , while the last table provides a breakdown of the related income statement impacts for the three and six months ended June 30, 2015 and 2014 . Fair Value of Derivative Instruments June 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 $ 66 $ 2 Natural gas derivatives (1) (2) Other Assets: Non-trading derivative assets 33 — Natural gas derivatives (1) (2) Current Liabilities: Non-trading derivative liabilities 8 43 Natural gas derivatives (1) (2) Other Liabilities: Non-trading derivative liabilities 2 19 Indexed debt securities derivative Current Liabilities — 583 Total $ 109 $ 647 _____________ (1) The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 718 billion cubic feet (Bcf) or a net 77 Bcf long position. Of the net long position, basis swaps constitute 118 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 $84 million asset as shown on CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above, offset by collateral netting of $39 million . Offsetting of Natural Gas Derivative Assets and Liabilities June 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 $ 74 $ (10 ) $ 64 Other Assets: Non-trading derivative assets 35 (2 ) 33 Current Liabilities: Non-trading derivative liabilities (45 ) 38 (7 ) Other Liabilities: Non-trading derivative liabilities (19 ) 13 (6 ) Total $ 45 $ 39 $ 84 ________________ (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 Indexed debt securities derivative Current Liabilities — 541 Total $ 149 $ 643 _______________ (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 CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above, offset by collateral netting of $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. Realized and unrealized gains and losses on indexed debt securities are recorded as Other Income (Expense) in the Condensed Statements of Consolidated Income. Income Statement Impact of Derivative Activity Three Months Ended June 30, Total derivatives not designated Income Statement Location 2015 2014 (in millions) Natural gas derivatives Gains (Losses) in Revenues $ 7 $ 5 Natural gas derivatives (1) Gains (Losses) in Expenses: Natural Gas 1 4 Indexed debt securities derivative Gains (Losses) in Other Income (Expense) (91 ) (50 ) Total $ (83 ) $ (41 ) ________________ (1) The Gains (Losses) in Expenses: Natural Gas includes $-0- during each of the three months ended June 30, 2015 and 2014 related to physical forwards purchased from Enable. Income Statement Impact of Derivative Activity Six Months Ended June 30, Total derivatives not designated as hedging instruments Income Statement Location 2015 2014 (in millions) Natural gas derivatives Gains (Losses) in Revenues $ 49 $ (96 ) Natural gas derivatives (1) Gains (Losses) in Expenses: Natural Gas (42 ) 114 Indexed debt securities derivative Gains (Losses) in Other Income (Expense) (67 ) (7 ) Total $ (60 ) $ 11 ________________ (1) The Gains (Losses) in Expenses: Natural Gas includes $-0- and $2 million during the six months ended June 30, 2015 and 2014 , respectively, related to physical forwards purchased from Enable. (c) Credit Risk Contingent Features CenterPoint Energy enters into financial derivative contracts containing material adverse change provisions. These provisions could require CenterPoint Energy to post additional collateral if the Standard & Poor’s Ratings Services or Moody’s Investors Service, Inc. credit ratings of CenterPoint Energy, Inc. or its subsidiaries are downgraded. The total fair value of the derivative instruments that contain credit risk contingent features that are in a net liability position at both June 30, 2015 and December 31, 2014 was $2 million . CenterPoint Energy posted no assets as collateral towards derivative instruments that contain credit risk contingent features at either June 30, 2015 or December 31, 2014 . If all derivative contracts (in a net liability position) containing credit risk contingent features were triggered at both June 30, 2015 and December 31, 2014 , $2 million of additional assets would be required to be posted as collateral.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 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 CenterPoint Energy’s Level 2 assets or liabilities. Level 3: Inputs are unobservable for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. Unobservable inputs reflect CenterPoint Energy’s judgments about the assumptions market participants would use in pricing the asset or liability since limited market data exists. CenterPoint Energy develops these inputs based on the best information available, including CenterPoint Energy’s own data. A market approach is utilized to value CenterPoint Energy’s Level 3 assets or liabilities. At June 30, 2015 , CenterPoint Energy’s Level 3 assets and liabilities are comprised of physical forward contracts and options. Level 3 physical forward contracts are valued using a discounted cash flow model which includes illiquid forward price curve locations (ranging from $1.26 to $3.79 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 71% ) as an unobservable input. CenterPoint Energy’s Level 3 derivative assets and liabilities consist of both long and short positions (forwards and options) and their fair value is sensitive to forward prices and volatilities. If forward prices decrease, CenterPoint Energy’s long forwards lose value whereas its short forwards gain in value. If volatility decreases, CenterPoint Energy’s long options lose value whereas its short options gain in value. CenterPoint Energy determines the appropriate level for each financial asset and liability on a quarterly basis and recognizes transfers between levels at the end of the reporting period. For the six months ended June 30, 2015 , there were no transfers between Level 1 and 2. CenterPoint Energy also recognizes purchases of Level 3 financial assets and liabilities at their fair market value at the end of the reporting period. The following tables present information about CenterPoint Energy’s assets and liabilities (including derivatives that are presented net) measured at fair value on a recurring basis as of June 30, 2015 and December 31, 2014 , and indicate the fair value hierarchy of the valuation techniques utilized by CenterPoint Energy to determine such fair value. Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Netting Adjustments (1) Balance as of June 30, 2015 (in millions) Assets Corporate equities $ 962 $ — $ — $ — $ 962 Investments, including money market funds (2) 28 — — — 28 Natural gas derivatives 2 96 11 (12 ) 97 Total assets $ 992 $ 96 $ 11 $ (12 ) $ 1,087 Liabilities Indexed debt securities derivative $ — $ 583 $ — $ — $ 583 Natural gas derivatives 10 53 1 (51 ) 13 Total liabilities $ 10 $ 636 $ 1 $ (51 ) $ 596 ________________ (1) Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $39 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 $ 932 $ — $ — $ — $ 932 Investments, including money market funds (2) 54 — — — 54 Natural gas derivatives 7 122 20 (18 ) 131 Total assets $ 993 $ 122 $ 20 $ (18 ) $ 1,117 Liabilities Indexed debt securities derivative $ — $ 541 $ — $ — $ 541 Natural gas derivatives 22 77 3 (82 ) 20 Total liabilities $ 22 $ 618 $ 3 $ (82 ) $ 561 ________________ (1) Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $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 CenterPoint Energy has utilized Level 3 inputs to determine fair value: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Derivative assets and liabilities, net Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions) Beginning balance $ 13 $ 1 $ 17 $ 3 Total gains — 2 — — Total settlements (3 ) 1 (6 ) 2 Transfers into Level 3 — — — (1 ) Transfers out of Level 3 — — (1 ) — Ending balance (1) $ 10 $ 4 $ 10 $ 4 The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date $ — $ 1 $ 2 $ 2 ________________ (1) CenterPoint Energy did not have significant Level 3 purchases or sales during either of the three or six months ended June 30, 2015 or 2014 . Estimated Fair Value of Financial Instruments The fair values of cash and cash equivalents, investments in debt and equity securities classified as “trading” and short-term borrowings are estimated to be approximately equivalent to carrying amounts and have been excluded from the table below. The carrying amounts of non-trading derivative assets and liabilities and CenterPoint Energy’s 2.0% Zero-Premium Exchangeable Subordinated Notes due 2029 (ZENS) indexed debt securities derivative are stated at fair value and are excluded from the table below. The fair value of each debt instrument is determined by multiplying the principal amount of each debt instrument by the market price. These assets and liabilities, which are not measured at fair value in the Condensed Consolidated Balance Sheets but for which the fair value is disclosed, would be classified as Level 1 or Level 2 in the fair value hierarchy. June 30, 2015 December 31, 2014 Carrying Fair Carrying Amount Fair Value (in millions) Financial assets: Notes receivable - affiliated companies $ 363 $ 363 $ 363 $ 362 Financial liabilities: Long-term debt $ 8,392 $ 8,934 $ 8,652 $ 9,427

Unconsolidated Affiliates (Note

Unconsolidated Affiliates (Notes)	6 Months Ended
	Jun. 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. and ArcLight Capital Partners, LLC closed on the formation of Enable. CenterPoint Energy 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. CenterPoint Energy’s maximum exposure to loss related to Enable, a VIE in which CenterPoint Energy is not the primary beneficiary, is limited to its equity investment as presented in the Condensed Consolidated Balance Sheet at June 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 13 , 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. CenterPoint Energy recorded interest income of $2 million during each of the three months ended June 30, 2015 and 2014 , and $4 million during each of the six months ended June 30, 2015 and 2014 , and had interest receivable from Enable of $5 million and $4 million as of June 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, CenterPoint Energy 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. CenterPoint Energy 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 CenterPoint Energy. During the fourth quarter of 2014, Enable notified CenterPoint Energy that it provided employment offers to substantially all of the seconded employees from CenterPoint Energy. Substantially all of the seconded employees became employees of Enable effective January 1, 2015. In accordance with the Enable formation agreements, CenterPoint Energy 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 CenterPoint Energy on the Closing Date, under which CenterPoint Energy 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 CenterPoint Energy to Enable or from Enable to CenterPoint Energy, 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. CenterPoint Energy billed Enable for reimbursement of transition services, including the costs of seconded employees, $2 million and $37 million during the three months ended June 30, 2015 and 2014 , respectively, and $7 million and $82 million during the six months ended June 30, 2015 and 2014 , respectively, under the Transition Agreements. Actual transition services costs are recorded net of reimbursements received from Enable. CenterPoint Energy had accounts receivable from Enable of $4 million and $28 million as of June 30, 2015 and December 31, 2014 , respectively, for amounts billed for transition services, including the cost of seconded employees. CenterPoint Energy incurred natural gas expenses, including transportation and storage costs, of $26 million and $27 million during the three months ended June 30, 2015 and 2014 , respectively, and $65 million and $75 million during the six months ended June 30, 2015 and 2014 , respectively, for transactions with Enable. CenterPoint Energy had accounts payable to Enable of $7 million and $23 million at June 30, 2015 and December 31, 2014 , respectively, from such transactions. As of June 30, 2015 , CenterPoint Energy held an approximate 55.4% limited partner interest in Enable, consisting of 94,151,707 common units and 139,704,916 subordinated units. CenterPoint Energy evaluates its equity method investments for impairment when factors indicate that a decrease in 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 the best estimate of 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 an analysis of its investment in Enable as of June 30, 2015 , CenterPoint Energy believes that the decline in the value of its investment is temporary, and that the carrying value of its investment of $4.5 billion will be recovered. CenterPoint Energy considered the severity and duration of the impairment, management’s intent and ability to hold its investment to recovery, significant events and conditions of Enable, including its investment grade credit rating and planned expansion projects, along with other factors, to conclude that its investment is not other than temporarily impaired as of June 30, 2015 . A sustained low Enable common unit price or further declines in such price could result in CenterPoint Energy recording an impairment charge in future periods. If the decrease in value of CenterPoint Energy’s investment in Enable is determined to be other than temporary, an impairment will be recognized equal to the excess of the carrying value of CenterPoint Energy’s investment in Enable over its estimated fair value. Both the income approach and market approach would be utilized to estimate the fair value of CenterPoint Energy’s total investment in Enable, which includes CenterPoint Energy’s limited partner common and subordinated units, general partner interest and incentive distribution rights. The determination of fair value will consider a number of relevant factors including Enable’s forecasted results, recent comparable transactions and the limited float of Enable’s publicly traded common units. As of June 30, 2015 , the carrying value of CenterPoint Energy’s investment in Enable was $19.12 per unit. On June 30, 2015 , Enable’s common unit price closed at $15.98 , based on its publicly traded common units which represent approximately 7% of total outstanding units, (an aggregate of approximately $734 million below carrying value). On July 31, 2015, Enable’s common unit price closed at $16.36 (approximately $645 million below carrying value). Investment in Unconsolidated Affiliates: June 30, December 31, 2014 (in millions) Enable $ 4,471 $ 4,520 SESH (1) — 1 Total $ 4,471 $ 4,521 (1) CenterPoint Energy disposed of its remaining interest in SESH on June 30, 2015. Equity in Earnings of Unconsolidated Affiliates, net: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions) Enable $ 43 $ 69 $ 95 $ 157 SESH (1) — 2 — 5 Total $ 43 $ 71 $ 95 $ 162 (1) CenterPoint Energy disposed of its remaining interest in SESH on June 30, 2015. Summarized unaudited consolidated income information for Enable is as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions) Operating revenues $ 590 $ 826 $ 1,206 $ 1,828 Cost of sales, excluding depreciation and amortization 277 478 569 1,111 Operating income 93 139 197 301 Net income attributable to Enable 77 120 168 269 CenterPoint Energy’s interest $ 42 $ 67 $ 93 $ 154 Basis difference accretion 1 2 2 3 CenterPoint Energy’s equity in earnings, net $ 43 $ 69 $ 95 $ 157 Summarized unaudited consolidated balance sheet information for Enable is as follows: June 30, December 31, 2014 (in millions) Current assets $ 414 $ 438 Non-current assets 11,766 11,399 Current liabilities 834 671 Non-current liabilities 2,611 2,343 Non-controlling interest 31 31 Enable partners’ capital 8,704 8,792 CenterPoint Energy’s ownership interest in Enable partners’ capital $ 4,817 $ 4,869 CenterPoint Energy’s basis difference attributable to goodwill (1) (217 ) (217 ) CenterPoint Energy’s accretable basis difference (2) (129 ) (132 ) CenterPoint Energy’s total basis difference (346 ) (349 ) CenterPoint Energy’s investment in Enable $ 4,471 $ 4,520 (1) The difference relates to CenterPoint Energy’s proportionate share of Enable’s goodwill arising from its acquisition of Enogex LLC, and therefore will be recognized by CenterPoint Energy upon dilution or disposition of its interest in Enable. (2) The difference will be recognized by CenterPoint Energy over 30 years beginning May 1, 2013. CenterPoint Energy will also adjust the accretable basis difference for dilution or disposition of its interest in Enable. Distributions Received from Unconsolidated Affiliates: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions) Enable $ 73 $ 90 $ 145 $ 157 SESH (1) — 4 — 7 Total $ 73 $ 94 $ 145 $ 164 (1) CenterPoint Energy disposed of its remaining interest in SESH on June 30, 2015.

Goodwill

Goodwill	6 Months Ended
	Jun. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	Goodwill Goodwill by reportable business segment as of both June 30, 2015 and December 31, 2014 is as follows (in millions): Natural Gas Distribution $ 746 Energy Services 83 Other Operations 11 Total $ 840

Capital Stock

Capital Stock	6 Months Ended
	Jun. 30, 2015
Class of Stock Disclosures [Abstract]
Capital Stock	Capital Stock CenterPoint Energy, Inc. has 1,020,000,000 authorized shares of capital stock, comprised of 1,000,000,000 shares of $0.01 par value common stock and 20,000,000 shares of $0.01 par value cumulative preferred stock. At June 30, 2015 , 430,260,023 shares of CenterPoint Energy, Inc. common stock were issued and 430,259,857 shares were outstanding. At December 31, 2014 , 429,795,996 shares of CenterPoint Energy, Inc. common stock were issued and 429,795,830 shares were outstanding. Outstanding common shares exclude 166 treasury shares at both June 30, 2015 and December 31, 2014 .

Indexed Debt Securities (ZENS)

Indexed Debt Securities (ZENS) and Securities Related to ZENS (Notes)	6 Months Ended
	Jun. 30, 2015
Indexed Debt Securities [Text Block]	Indexed Debt Securities (ZENS) and Securities Related to ZENS In September 1999, CenterPoint Energy issued ZENS having an original principal amount of $1.0 billion of which $828 million remains outstanding at June 30, 2015 . Each ZENS note was originally exchangeable at the holder’s option at any time for an amount of cash equal to 95% of the market value of the reference shares of Time Warner Inc. common stock (TW Common) attributable to such note. The number and identity of the reference shares attributable to each ZENS note are adjusted for certain corporate events. Prior to the closing of the merger discussed below, the reference shares for each ZENS note consisted of 0.5 share of TW Common, 0.125505 share of Time Warner Cable Inc. (TWC) common stock (TWC Common), 0.045455 share of AOL Inc. common stock (AOL Common) and 0.0625 share of Time Inc. common stock (Time Common). On May 26, 2015, Verizon Communications, Inc. (Verizon) initiated a tender offer to purchase all outstanding shares of AOL Common for $50 per share, in which CenterPoint Energy tendered all of its shares of AOL Common for $32 million . Verizon acquired the remaining eligible shares through a merger, which closed on June 23, 2015. In accordance with the terms of the ZENS, CenterPoint Energy remitted $32 million to ZENS holders in July 2015, which reduced contingent principal. As a result, CenterPoint Energy recorded a reduction in the indexed debt securities derivative liability of $18 million , a reduction in the indexed debt balance of $7 million and a loss of $7 million , which is included in Loss on indexed debt securities on the Condensed Statements of Consolidated Income. As of June 30, 2015, the reference shares for each ZENS note consisted of 0.5 share of TW Common, 0.125505 share of TWC Common and 0.0625 share of Time Common and the contingent principal balance was $744 million . On May 26, 2015, Charter Communications, Inc. (Charter) announced that it had entered into a definitive merger agreement with TWC, and that the merger is expected to close by the end of the year. Pursuant to the merger agreement, TWC Common shares would be exchanged for cash and Charter stock. Upon closing of the merger, reference shares would consist of Charter stock, TW Common and Time Common.

Short-Term Borrowings and Long-

Short-Term Borrowings and Long-term Debt	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Short-term Borrowings and Long-term Debt [Text Block]	Short-term Borrowings and Long-term Debt (a) Short-term Borrowings Inventory Financing . 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 $24 million and $53 million as of June 30, 2015 and December 31, 2014 , respectively. (b) Long-term Debt Debt Repayments. In June 2015, CenterPoint Energy repaid its $200 million 6.85% Senior Notes using proceeds from its commercial paper program. CenterPoint Energy’s $1.2 billion revolving credit facility backstops its $1.0 billion commercial paper program. Credit Facilities. As of June 30, 2015 and December 31, 2014 , CenterPoint Energy, CenterPoint Houston and CERC Corp. had the following revolving credit facilities and utilization of such facilities (in millions): June 30, 2015 December 31, 2014 Size of Loans Letters Commercial Loans Letters Commercial CenterPoint Energy $ 1,200 $ — $ 6 $ 596 $ — $ 6 $ 191 CenterPoint Houston 300 — 4 — — 4 — CERC Corp. 600 — — 72 — — 341 Total $ 2,100 $ — $ 10 $ 668 $ — $ 10 $ 532 CenterPoint Energy’s $1.2 billion revolving credit facility, which is scheduled to terminate on September 9, 2019 , can be drawn at the London Interbank Offered Rate (LIBOR) plus 1.25% based on CenterPoint Energy’s current credit ratings. The revolving credit facility contains a financial covenant which limits CenterPoint Energy’s consolidated debt (excluding transition and system restoration bonds) to an amount not to exceed 65% of CenterPoint Energy’s consolidated capitalization. The financial covenant limit will temporarily increase from 65% to 70% if CenterPoint Houston experiences damage from a natural disaster in its service territory and CenterPoint Energy certifies to the administrative agent that CenterPoint Houston has incurred system restoration costs reasonably likely to exceed $100 million in a consecutive twelve -month period, all or part of which CenterPoint Houston intends to seek to recover through securitization financing. Such temporary increase in the financial covenant would be in effect from the date CenterPoint Energy delivers its certification until the earliest to occur of (i) the completion of the securitization financing, (ii) the first anniversary of CenterPoint Energy’s certification or (iii) the revocation of such certification. CenterPoint Houston’s $300 million revolving credit facility, which is scheduled to terminate on September 9, 2019 , can be drawn at LIBOR plus 1.125% based on CenterPoint Houston’s current credit ratings. The revolving credit facility contains a financial covenant which limits CenterPoint Houston’s consolidated debt (excluding transition and system restoration bonds) to an amount not to exceed 65% of CenterPoint Houston’s consolidated capitalization. CERC Corp.’s $600 million revolving credit facility, which is scheduled to terminate on September 9, 2019 , can be drawn at LIBOR 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. CenterPoint Energy, CenterPoint Houston and CERC Corp. were in compliance with all financial covenants as of June 30, 2015 .

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective tax rate reported for the three months ended June 30, 2015 was 32% compared to 37% for the same period in 2014. The lower effective tax rate for the three and six months ended June 30, 2015 was primarily due to the lower Texas tax rate enacted on June 15, 2015 and favorable permanent book-tax differences. The effective tax rate reported for the six months ended June 30, 2015 was 36% compared to 37% for the same period in 2014. CenterPoint Energy reported no uncertain tax liability as of June 30, 2015 and expects no significant change to the uncertain tax liability over the twelve-month period ending June 30, 2016. Tax years through 2011 have been audited and settled with the Internal Revenue Service (IRS). The consolidated federal income tax returns for the years 2012 and 2013 are currently under audit by the IRS. For 2014 and 2015, CenterPoint Energy is a participant in the IRS’s Compliance Assurance Process.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 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 CenterPoint Energy’s Natural Gas Distribution and Energy Services business segments, which have various quantity requirements and durations, that are not classified as non-trading derivative assets and liabilities in CenterPoint Energy’s Consolidated Balance Sheets as of June 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 June 30, 2015 , minimum payment obligations for natural gas supply commitments are approximately $228 million for the remaining six months in 2015, $485 million in 2016, $471 million in 2017, $419 million in 2018, $227 million in 2019 and $130 million after 2019. (b) Legal, Environmental and Other Regulatory Matters Legal Matters Gas Market Manipulation Cases . CenterPoint Energy, CenterPoint Houston or their predecessor, Reliant Energy, Incorporated (Reliant Energy), and certain of their former subsidiaries have been named as defendants in certain lawsuits described below. Under a master separation agreement between CenterPoint Energy and a former subsidiary, Reliant Resources, Inc. (RRI), CenterPoint Energy and its subsidiaries are entitled to be indemnified by RRI and its successors for any losses, including certain attorneys’ fees and other costs, arising out of these lawsuits. In May 2009, RRI sold its Texas retail business to a subsidiary of NRG 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. CenterPoint Energy does not expect the ultimate outcome of this matter to have a material adverse effect on its financial condition, results of operations or cash flows. 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 June 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 CenterPoint Energy contain or have contained asbestos insulation and other asbestos-containing materials. CenterPoint Energy or its subsidiaries have been named, along with numerous others, as a defendant in lawsuits filed by a number of individuals who claim injury due to exposure to asbestos. Some of the claimants have worked at locations owned by subsidiaries of CenterPoint Energy, but most existing claims relate to facilities previously owned by CenterPoint Energy’s subsidiaries. In 2004 and early 2005, CenterPoint Energy sold its generating business, to which most of these claims relate, to a company which is now an affiliate of NRG. Under the terms of the arrangements regarding separation of the generating business from CenterPoint Energy and its sale of that business, ultimate financial responsibility for uninsured losses from claims relating to the generating business has been assumed by the NRG affiliate, but CenterPoint Energy has agreed to continue to defend such claims to the extent they are covered by insurance maintained by CenterPoint Energy, subject to reimbursement of the costs of such defense by the NRG affiliate. CenterPoint Energy anticipates that additional claims like those received may be asserted in the future. Although their ultimate outcome cannot be predicted at this time, CenterPoint Energy intends to continue vigorously contesting claims that it does not consider to have merit and, based on its experience to date, does not expect these matters, either individually or in the aggregate, to have a material adverse effect on CenterPoint Energy’s financial condition, results of operations or cash flows. Other Environmental. From time to time CenterPoint Energy identifies the presence of environmental contaminants on property where its subsidiaries conduct or have conducted operations. Other such sites involving contaminants may be identified in the future. CenterPoint Energy has and expects to continue to remediate identified sites consistent with its legal obligations. From time to time CenterPoint Energy has received notices from regulatory authorities or others regarding its status as a PRP in connection with sites found to require remediation due to the presence of environmental contaminants. In addition, CenterPoint Energy has been named from time to time as a defendant in litigation related to such sites. Although the ultimate outcome of such matters cannot be predicted at this time, CenterPoint Energy does not expect, based on its experience to date, these matters, either individually or in the aggregate, to have a material adverse effect on CenterPoint Energy’s financial condition, results of operations or cash flows. Other Proceedings CenterPoint Energy is involved in other legal, environmental, tax and regulatory proceedings before various courts, regulatory commissions and governmental agencies regarding matters arising in the ordinary course of business. From time to time, CenterPoint Energy is also a defendant in legal proceedings with respect to claims brought by various plaintiffs against broad groups of participants in the energy industry. Some of these proceedings involve substantial amounts. CenterPoint Energy regularly analyzes current information and, as necessary, provides accruals for probable liabilities on the eventual disposition of these matters. CenterPoint Energy does not expect the disposition of these matters to have a material adverse effect on CenterPoint Energy’s financial condition, results of operations or cash flows. (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 $36 million as of June 30, 2015 . Based on market conditions in the fourth quarter of 2014 at the time the most recent annual calculation was made under the agreement, GenOn was not obligated to post any security. If GenOn should fail to perform the contractual obligations, CERC could have to honor its guarantee and, in such event, any collateral then provided as security may be insufficient to satisfy CERC’s obligations. CenterPoint Energy has provided guarantees (CenterPoint Midstream Guarantees) with respect to the performance of certain obligations of Enable under long-term gas gathering and treating agreements with an indirect wholly owned subsidiary of Encana Corporation and an indirect wholly owned subsidiary of Royal Dutch Shell plc. As of June 30, 2015 , CenterPoint Energy had guaranteed Enable’s obligations up to an aggregate amount of $100 million under these agreements. Under the terms of the omnibus agreement entered into in connection with the closing of the formation of Enable, Enable and CenterPoint Energy have agreed to use commercially reasonable efforts and cooperate with each other to terminate the CenterPoint Midstream Guarantees and to release CenterPoint Energy from such guarantees by causing Enable or one of its subsidiaries to enter into substitute guarantees or to assume the CenterPoint Midstream Guarantees as applicable. 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.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table reconciles numerators and denominators of CenterPoint Energy’s basic and diluted earnings per share calculations: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions, except share and per share amounts) Net income $ 77 $ 107 $ 208 $ 292 Basic weighted average shares outstanding 430,235,000 429,773,000 430,096,000 429,470,000 Plus: Incremental shares from assumed conversions: Restricted stock 1,498,000 1,636,000 1,498,000 1,636,000 Diluted weighted average shares 431,733,000 431,409,000 431,594,000 431,106,000 Basic earnings per share: Net income $ 0.18 $ 0.25 $ 0.48 $ 0.68 Diluted earnings per share: Net income $ 0.18 $ 0.25 $ 0.48 $ 0.68

Reportable Business Segments

Reportable Business Segments	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Reportable Business Segments	Reportable Business Segments CenterPoint Energy’s determination of reportable business segments considers the strategic operating units under which CenterPoint Energy manages sales, allocates resources and assesses performance of various products and services to wholesale or retail customers in differing regulatory environments. CenterPoint Energy uses operating income as the measure of profit or loss for its business segments. CenterPoint Energy’s reportable business segments include the following: Electric Transmission & Distribution, Natural Gas Distribution, Energy Services, Midstream Investments and Other Operations. The electric transmission and distribution function (CenterPoint Houston) is reported in the Electric Transmission & Distribution business segment. Natural Gas Distribution consists of intrastate natural gas sales to, and natural gas transportation and distribution for, residential, commercial, industrial and institutional customers. Energy Services represents CenterPoint Energy’s non-rate regulated gas sales and services operations. Midstream Investments consists of CenterPoint Energy’s investment in Enable. Other Operations consists primarily of other corporate operations which support all of CenterPoint Energy’s business operations. Financial data for business segments is as follows (in millions): For the Three Months Ended June 30, 2015 Revenues from Net Operating Electric Transmission & Distribution $ 705 (1) $ — $ 158 Natural Gas Distribution 420 7 19 Energy Services 404 4 9 Midstream Investments (2) — — — Other Operations 3 — — Eliminations — (11 ) — Consolidated $ 1,532 $ — $ 186 For the Three Months Ended June 30, 2014 Revenues from Net Operating Electric Transmission & Distribution $ 698 (1) $ — $ 145 Natural Gas Distribution 526 6 30 Energy Services 657 19 11 Midstream Investments (2) — — — Other Operations 3 — — Eliminations — (25 ) — Consolidated $ 1,884 $ — $ 186 For the Six Months Ended June 30, 2015 Revenues from External Customers Net Intersegment Revenues Operating Income Total Assets as of June 30, 2015 Electric Transmission & Distribution $ 1,317 (1) $ — $ 254 $ 9,944 Natural Gas Distribution 1,605 15 165 5,301 Energy Services 1,036 22 22 837 Midstream Investments (2) — — — 4,471 Other Operations 7 — 1 2,999 (3) Eliminations — (37 ) — (950 ) Consolidated $ 3,965 $ — $ 442 $ 22,602 For the Six Months Ended June 30, 2014 Revenues from Net Operating Total Assets as of December 31, 2014 Electric Transmission & Distribution $ 1,327 (1) $ — $ 250 $ 10,066 Natural Gas Distribution 2,004 15 192 5,464 Energy Services 1,709 51 37 978 Midstream Investments (2) — — — 4,521 Other Operations 7 — 2 3,368 (3) Eliminations — (66 ) — (1,197 ) Consolidated $ 5,047 $ — $ 481 $ 23,200 ________________ (1) CenterPoint Houston’s transmission and distribution revenues from major customers are as follows (in millions): Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Affiliates of NRG $ 172 $ 164 $ 356 $ 330 Affiliates of Energy Future Holdings Corp. $ 51 $ 41 $ 103 $ 81 (2) Midstream Investments’ equity earnings are as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions) Enable $ 43 $ 69 $ 95 $ 157 SESH — 2 — 5 Total $ 43 $ 71 $ 95 $ 162 Midstream Investments’ total assets are as follows: June 30, December 31, 2014 (in millions) Enable $ 4,471 $ 4,520 SESH — 1 Total $ 4,471 $ 4,521 (3) Included in total assets of Other Operations as of June 30, 2015 and December 31, 2014 are pension and other postemployment related regulatory assets of $757 million and $795 million , respectively.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2015
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events On July 24, 2015 , CenterPoint Energy’s board of directors declared a regular quarterly cash dividend of $0.2475 per share of common stock payable on September 10, 2015 , to shareholders of record as of the close of business on August 14, 2015 . On July 22, 2015 , Enable declared a quarterly cash distribution of $0.316 per unit on all of its outstanding common and subordinated units for the quarter ended June 30, 2015 . Accordingly, CERC Corp. expects to receive a cash distribution of approximately $74 million from Enable in the third quarter of 2015 to be made with respect to CERC Corp.’s limited partner interest in Enable for the second quarter of 2015.

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	6 Months Ended
	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Schedule of Defined Benefit Plans Disclosures [Table Text Block]	CenterPoint Energy’s net periodic cost includes the following components relating to pension and postretirement benefits: Three Months Ended June 30, 2015 2014 Pension Postretirement Pension Postretirement (in millions) Service cost $ 10 $ — $ 11 $ 1 Interest cost 23 5 25 5 Expected return on plan assets (30 ) (1 ) (31 ) (2 ) Amortization of prior service cost (credit) 2 (1 ) 2 (1 ) Amortization of net loss 15 1 11 1 Amortization of transition obligation — — — 2 Net periodic cost $ 20 $ 4 $ 18 $ 6 Six Months Ended June 30, 2015 2014 Pension Benefits (1) Postretirement Benefits (1) Pension Benefits (1) Postretirement Benefits (1) (in millions) Service cost $ 20 $ 1 $ 21 $ 1 Interest cost 46 10 50 11 Expected return on plan assets (60 ) (3 ) (62 ) (4 ) Amortization of prior service cost (credit) 5 (1 ) 5 (1 ) Amortization of net loss 29 2 22 1 Amortization of transition obligation — — — 3 Settlement cost (2) 9 — — — Net periodic cost $ 49 $ 9 $ 36 $ 11 ________________ (1) Net periodic cost in these tables is before considering amounts subject to overhead allocations for capital expenditure projects or for amounts subject to deferral for regulatory purposes. (2) A one-time, non-cash settlement charge is required when lump sum distributions or other settlements of plan benefit obligations during a plan year exceed the service cost and interest cost components of net periodic cost for that year. Due to the amount of lump sum payment distributions from the non-qualified pension plan during the six months ended June 30, 2015 , CenterPoint Energy recognized a non-cash settlement charge of $9 million . This charge is an acceleration of costs that would otherwise be recognized in future periods. CenterPoint Energy will continue to recognize incremental settlement costs in subsequent quarters as additional lump sum distributions are made under the non-qualified pension plan. CenterPoint Energy’s changes in accumulated comprehensive loss related to defined benefit and postretirement plans are as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Pension and Postretirement Plans Pension and Postretirement Plans (in millions) Beginning Balance $ (83 ) $ (87 ) $ (85 ) $ (88 ) Amounts reclassified from accumulated other comprehensive loss: Prior service cost (1) — 1 — 1 Actuarial losses (1) 2 3 6 5 Total reclassifications from accumulated other comprehensive loss 2 4 6 6 Tax expense — (2 ) (2 ) (3 ) Net current period other comprehensive income 2 2 4 3 Ending Balance $ (81 ) $ (85 ) $ (81 ) $ (85 ) ________________ (1) These components are included in the computation of net periodic cost.

Derivative Instruments (Tables)

Derivative Instruments (Tables)	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Instruments	Fair Value of Derivative Instruments June 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 $ 66 $ 2 Natural gas derivatives (1) (2) Other Assets: Non-trading derivative assets 33 — Natural gas derivatives (1) (2) Current Liabilities: Non-trading derivative liabilities 8 43 Natural gas derivatives (1) (2) Other Liabilities: Non-trading derivative liabilities 2 19 Indexed debt securities derivative Current Liabilities — 583 Total $ 109 $ 647 _____________ (1) The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 718 billion cubic feet (Bcf) or a net 77 Bcf long position. Of the net long position, basis swaps constitute 118 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 $84 million asset as shown on CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above, offset by collateral netting of $39 million . 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 Indexed debt securities derivative Current Liabilities — 541 Total $ 149 $ 643 _______________ (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 CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above, offset by collateral netting of $64 million .
Offsetting of Natural Gas Derivative Assets and Liabilities	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. Offsetting of Natural Gas Derivative Assets and Liabilities June 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 $ 74 $ (10 ) $ 64 Other Assets: Non-trading derivative assets 35 (2 ) 33 Current Liabilities: Non-trading derivative liabilities (45 ) 38 (7 ) Other Liabilities: Non-trading derivative liabilities (19 ) 13 (6 ) Total $ 45 $ 39 $ 84 ________________ (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.
Income Statement Impact of Derivative Activity	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. Realized and unrealized gains and losses on indexed debt securities are recorded as Other Income (Expense) in the Condensed Statements of Consolidated Income. Income Statement Impact of Derivative Activity Three Months Ended June 30, Total derivatives not designated Income Statement Location 2015 2014 (in millions) Natural gas derivatives Gains (Losses) in Revenues $ 7 $ 5 Natural gas derivatives (1) Gains (Losses) in Expenses: Natural Gas 1 4 Indexed debt securities derivative Gains (Losses) in Other Income (Expense) (91 ) (50 ) Total $ (83 ) $ (41 ) ________________ (1) The Gains (Losses) in Expenses: Natural Gas includes $-0- during each of the three months ended June 30, 2015 and 2014 related to physical forwards purchased from Enable. Income Statement Impact of Derivative Activity Six Months Ended June 30, Total derivatives not designated as hedging instruments Income Statement Location 2015 2014 (in millions) Natural gas derivatives Gains (Losses) in Revenues $ 49 $ (96 ) Natural gas derivatives (1) Gains (Losses) in Expenses: Natural Gas (42 ) 114 Indexed debt securities derivative Gains (Losses) in Other Income (Expense) (67 ) (7 ) Total $ (60 ) $ 11 ________________ (1) The Gains (Losses) in Expenses: Natural Gas includes $-0- and $2 million during the six months ended June 30, 2015 and 2014 , respectively, related to physical forwards purchased from Enable.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair value, assets measured on a recurring basis	The following tables present information about CenterPoint Energy’s assets and liabilities (including derivatives that are presented net) measured at fair value on a recurring basis as of June 30, 2015 and December 31, 2014 , and indicate the fair value hierarchy of the valuation techniques utilized by CenterPoint Energy to determine such fair value. Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Netting Adjustments (1) Balance as of June 30, 2015 (in millions) Assets Corporate equities $ 962 $ — $ — $ — $ 962 Investments, including money market funds (2) 28 — — — 28 Natural gas derivatives 2 96 11 (12 ) 97 Total assets $ 992 $ 96 $ 11 $ (12 ) $ 1,087 Liabilities Indexed debt securities derivative $ — $ 583 $ — $ — $ 583 Natural gas derivatives 10 53 1 (51 ) 13 Total liabilities $ 10 $ 636 $ 1 $ (51 ) $ 596 ________________ (1) Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $39 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 $ 932 $ — $ — $ — $ 932 Investments, including money market funds (2) 54 — — — 54 Natural gas derivatives 7 122 20 (18 ) 131 Total assets $ 993 $ 122 $ 20 $ (18 ) $ 1,117 Liabilities Indexed debt securities derivative $ — $ 541 $ — $ — $ 541 Natural gas derivatives 22 77 3 (82 ) 20 Total liabilities $ 22 $ 618 $ 3 $ (82 ) $ 561 ________________ (1) Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $64 million posted with the same counterparties. (2) Amounts are included in Prepaid Expenses and Other Current Assets in the Condensed Consolidated Balance Sheets.
Assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs	The following table presents additional information about assets or liabilities, including derivatives that are measured at fair value on a recurring basis for which CenterPoint Energy has utilized Level 3 inputs to determine fair value: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Derivative assets and liabilities, net Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions) Beginning balance $ 13 $ 1 $ 17 $ 3 Total gains — 2 — — Total settlements (3 ) 1 (6 ) 2 Transfers into Level 3 — — — (1 ) Transfers out of Level 3 — — (1 ) — Ending balance (1) $ 10 $ 4 $ 10 $ 4 The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date $ — $ 1 $ 2 $ 2 ________________ (1) CenterPoint Energy did not have significant Level 3 purchases or sales during either of the three or six months ended June 30, 2015 or 2014 .
Estimated fair value of financial instruments, debt instruments	Estimated Fair Value of Financial Instruments The fair values of cash and cash equivalents, investments in debt and equity securities classified as “trading” and short-term borrowings are estimated to be approximately equivalent to carrying amounts and have been excluded from the table below. The carrying amounts of non-trading derivative assets and liabilities and CenterPoint Energy’s 2.0% Zero-Premium Exchangeable Subordinated Notes due 2029 (ZENS) indexed debt securities derivative are stated at fair value and are excluded from the table below. The fair value of each debt instrument is determined by multiplying the principal amount of each debt instrument by the market price. These assets and liabilities, which are not measured at fair value in the Condensed Consolidated Balance Sheets but for which the fair value is disclosed, would be classified as Level 1 or Level 2 in the fair value hierarchy. June 30, 2015 December 31, 2014 Carrying Fair Carrying Amount Fair Value (in millions) Financial assets: Notes receivable - affiliated companies $ 363 $ 363 $ 363 $ 362 Financial liabilities: Long-term debt $ 8,392 $ 8,934 $ 8,652 $ 9,427

Unconsolidated Affiliates (Tabl

Unconsolidated Affiliates (Tables)	6 Months Ended
	Jun. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments [Table Text Block]	Investment in Unconsolidated Affiliates: June 30, December 31, 2014 (in millions) Enable $ 4,471 $ 4,520 SESH (1) — 1 Total $ 4,471 $ 4,521 (1) CenterPoint Energy disposed of its remaining interest in SESH on June 30, 2015. Equity in Earnings of Unconsolidated Affiliates, net: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions) Enable $ 43 $ 69 $ 95 $ 157 SESH (1) — 2 — 5 Total $ 43 $ 71 $ 95 $ 162 (1) CenterPoint Energy disposed of its remaining interest in SESH on June 30, 2015. Summarized unaudited consolidated income information for Enable is as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions) Operating revenues $ 590 $ 826 $ 1,206 $ 1,828 Cost of sales, excluding depreciation and amortization 277 478 569 1,111 Operating income 93 139 197 301 Net income attributable to Enable 77 120 168 269 CenterPoint Energy’s interest $ 42 $ 67 $ 93 $ 154 Basis difference accretion 1 2 2 3 CenterPoint Energy’s equity in earnings, net $ 43 $ 69 $ 95 $ 157 Summarized unaudited consolidated balance sheet information for Enable is as follows: June 30, December 31, 2014 (in millions) Current assets $ 414 $ 438 Non-current assets 11,766 11,399 Current liabilities 834 671 Non-current liabilities 2,611 2,343 Non-controlling interest 31 31 Enable partners’ capital 8,704 8,792 CenterPoint Energy’s ownership interest in Enable partners’ capital $ 4,817 $ 4,869 CenterPoint Energy’s basis difference attributable to goodwill (1) (217 ) (217 ) CenterPoint Energy’s accretable basis difference (2) (129 ) (132 ) CenterPoint Energy’s total basis difference (346 ) (349 ) CenterPoint Energy’s investment in Enable $ 4,471 $ 4,520 (1) The difference relates to CenterPoint Energy’s proportionate share of Enable’s goodwill arising from its acquisition of Enogex LLC, and therefore will be recognized by CenterPoint Energy upon dilution or disposition of its interest in Enable. (2) The difference will be recognized by CenterPoint Energy over 30 years beginning May 1, 2013. CenterPoint Energy will also adjust the accretable basis difference for dilution or disposition of its interest in Enable. Distributions Received from Unconsolidated Affiliates: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions) Enable $ 73 $ 90 $ 145 $ 157 SESH (1) — 4 — 7 Total $ 73 $ 94 $ 145 $ 164 (1) CenterPoint Energy disposed of its remaining interest in SESH on June 30, 2015.

Goodwill (Tables)

Goodwill (Tables)	6 Months Ended
	Jun. 30, 2015
Goodwill [Line Items]
Schedule of Goodwill [Table Text Block]	Goodwill by reportable business segment as of both June 30, 2015 and December 31, 2014 is as follows (in millions): Natural Gas Distribution $ 746 Energy Services 83 Other Operations 11 Total $ 840

Short-Term Borrowings and Lon29

Short-Term Borrowings and Long-term Debt Credit Facilities (Tables)	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Schedule of Line of Credit Facilities [Table Text Block]	Credit Facilities. As of June 30, 2015 and December 31, 2014 , CenterPoint Energy, CenterPoint Houston and CERC Corp. had the following revolving credit facilities and utilization of such facilities (in millions): June 30, 2015 December 31, 2014 Size of Loans Letters Commercial Loans Letters Commercial CenterPoint Energy $ 1,200 $ — $ 6 $ 596 $ — $ 6 $ 191 CenterPoint Houston 300 — 4 — — 4 — CERC Corp. 600 — — 72 — — 341 Total $ 2,100 $ — $ 10 $ 668 $ — $ 10 $ 532

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table reconciles numerators and denominators of CenterPoint Energy’s basic and diluted earnings per share calculations: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions, except share and per share amounts) Net income $ 77 $ 107 $ 208 $ 292 Basic weighted average shares outstanding 430,235,000 429,773,000 430,096,000 429,470,000 Plus: Incremental shares from assumed conversions: Restricted stock 1,498,000 1,636,000 1,498,000 1,636,000 Diluted weighted average shares 431,733,000 431,409,000 431,594,000 431,106,000 Basic earnings per share: Net income $ 0.18 $ 0.25 $ 0.48 $ 0.68 Diluted earnings per share: Net income $ 0.18 $ 0.25 $ 0.48 $ 0.68

Reportable Business Segments (T

Reportable Business Segments (Tables)	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Financial data for business segments is as follows (in millions): For the Three Months Ended June 30, 2015 Revenues from Net Operating Electric Transmission & Distribution $ 705 (1) $ — $ 158 Natural Gas Distribution 420 7 19 Energy Services 404 4 9 Midstream Investments (2) — — — Other Operations 3 — — Eliminations — (11 ) — Consolidated $ 1,532 $ — $ 186 For the Three Months Ended June 30, 2014 Revenues from Net Operating Electric Transmission & Distribution $ 698 (1) $ — $ 145 Natural Gas Distribution 526 6 30 Energy Services 657 19 11 Midstream Investments (2) — — — Other Operations 3 — — Eliminations — (25 ) — Consolidated $ 1,884 $ — $ 186 For the Six Months Ended June 30, 2015 Revenues from External Customers Net Intersegment Revenues Operating Income Total Assets as of June 30, 2015 Electric Transmission & Distribution $ 1,317 (1) $ — $ 254 $ 9,944 Natural Gas Distribution 1,605 15 165 5,301 Energy Services 1,036 22 22 837 Midstream Investments (2) — — — 4,471 Other Operations 7 — 1 2,999 (3) Eliminations — (37 ) — (950 ) Consolidated $ 3,965 $ — $ 442 $ 22,602 For the Six Months Ended June 30, 2014 Revenues from Net Operating Total Assets as of December 31, 2014 Electric Transmission & Distribution $ 1,327 (1) $ — $ 250 $ 10,066 Natural Gas Distribution 2,004 15 192 5,464 Energy Services 1,709 51 37 978 Midstream Investments (2) — — — 4,521 Other Operations 7 — 2 3,368 (3) Eliminations — (66 ) — (1,197 ) Consolidated $ 5,047 $ — $ 481 $ 23,200
Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]	CenterPoint Houston’s transmission and distribution revenues from major customers are as follows (in millions): Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Affiliates of NRG $ 172 $ 164 $ 356 $ 330 Affiliates of Energy Future Holdings Corp. $ 51 $ 41 $ 103 $ 81
Midstream Investments [Table Text Block]	Midstream Investments’ equity earnings are as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions) Enable $ 43 $ 69 $ 95 $ 157 SESH — 2 — 5 Total $ 43 $ 71 $ 95 $ 162 Midstream Investments’ total assets are as follows: June 30, December 31, 2014 (in millions) Enable $ 4,471 $ 4,520 SESH — 1 Total $ 4,471 $ 4,521

Background and Basis of Prese32

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

New Accounting Pronouncements N

New Accounting Pronouncements New Accounting Pronouncements and Changes in Accounting Principles (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Other Noncurrent Assets [Member]
Unamortized Debt Issuance Expense	$ 57	$ 61

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Defined Benefit Plan, Change in Accumulated Comprehensive Loss [Roll Forward]
Beginning Balance		$ (83)	$ (87)	$ (85)	$ (88)
Amounts reclassified from accumulated other comprehensive loss:
Prior service cost (1)	[1]	0	1	0	1
Actuarial losses (1)	[1]	2	3	6	5
Total reclassifications from accumulated other comprehensive loss		2	4	6	6
Tax expense		0	(2)	(2)	(3)
Net current period other comprehensive income		2	2	4	3
Ending Balance		(81)	(85)	(81)	(85)
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	[2]	10	11	20	21
Interest cost	[2]	23	25	46	50
Expected return on plan assets	[2]	(30)	(31)	(60)	(62)
Amortization of prior service cost (credit)	[2]	2	2	5	5
Amortization of net loss	[2]	15	11	29	22
Amortization of transition obligation	[2]	0	0	0	0
Settlement cost (2)	[2],[3]			9	0
Net periodic cost	[2]	20	18	49	36
Total contributions to the plans during the period		2		25
Total contributions expected in 2014				66
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		0	1	1	1
Interest cost		5	5	10	11
Expected return on plan assets		(1)	(2)	(3)	(4)
Amortization of prior service cost (credit)		(1)	(1)	(1)	(1)
Amortization of net loss		1	1	2	1
Amortization of transition obligation		0	2	0	3
Settlement cost (2)	[3]			0	0
Net periodic cost		4	$ 6	9	$ 11
Total contributions to the plans during the period		$ 3		8
Total contributions expected in 2014				$ 17
[1]	These components are included in the computation of net periodic cost.
[2]	Net periodic cost in these tables is before considering amounts subject to overhead allocations for capital expenditure projects or for amounts subject to deferral for regulatory purposes.
[3]	A one-time, non-cash settlement charge is required when lump sum distributions or other settlements of plan benefit obligations during a plan year exceed the service cost and interest cost components of net periodic cost for that year. Due to the amount of lump sum payment distributions from the non-qualified pension plan during the six months ended June 30, 2015, CenterPoint Energy recognized a non-cash settlement charge of $9 million. This charge is an acceleration of costs that would otherwise be recognized in future periods. CenterPoint Energy will continue to recognize incremental settlement costs in subsequent quarters as additional lump sum distributions are made under the non-qualified pension plan.

Regulatory Accounting (Details)

Regulatory Accounting (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Amount of allowed equity return on the true-up balance that has not been recognized	$ 421		$ 421
Amount of allowed equity return on the true-up balance that was recognized in the period	$ 12	$ 17	$ 21	$ 32

Derivative Instruments Derivati

Derivative Instruments Derivatives and hedging (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivatives, Fair Value [Line Items]
Weather Hedges Term
Gains (Losses) in Revenue [Member] | Weather Hedge Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 1	$ 0	$ (9)	$ (8)
2014To2015 [Member] | Electric Transmission and Distribution [Member]
Derivatives, Fair Value [Line Items]
Weather Hedge, Bilateral Cap Amount			8
2014To2015 [Member] | Natural Gas Distribution [Member]
Derivatives, Fair Value [Line Items]
Weather Hedge, Bilateral Cap Amount			16
2013To2014 [Member] | Electric Transmission and Distribution [Member]
Derivatives, Fair Value [Line Items]
Weather Hedge, Bilateral Cap Amount			8
2013To2014 [Member] | Natural Gas Distribution [Member]
Derivatives, Fair Value [Line Items]
Weather Hedge, Bilateral Cap Amount			$ 16

Derivative Fair Values (Details

Derivative Fair Values (Details) MMcf in Thousands		3 Months Ended				6 Months Ended				12 Months Ended
		Jun. 30, 2015USD ($)		Jun. 30, 2014USD ($)		Jun. 30, 2015USD ($)MMcf		Jun. 30, 2014USD ($)		Dec. 31, 2014USD ($)MMcf
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Asset, Fair Value		$ 109,000,000				$ 109,000,000				$ 149,000,000
Indexed debt securities derivative		647,000,000				647,000,000				643,000,000
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		(83,000,000)		$ (41,000,000)		(60,000,000)		$ 11,000,000
Derivative, Fair Value, Net [Abstract]
Total fair value of the derivative instruments that contain credit risk contingent features that are in a net liability position		2,000,000				2,000,000				2,000,000
The aggregate fair value of assets already posted as collateral		0				0				0
Credit Risk Contingent Features assets		2,000,000				$ 2,000,000				$ 2,000,000
Natural gas derivatives [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative, Nonmonetary Notional Amount, Volume | MMcf						718				804
Derivative, Fair Value, Net [Abstract]
Gross Amounts Recognized	[1]	45,000,000				$ 45,000,000				$ 47,000,000
Gross amounts offset, Net		39,000,000				39,000,000				64,000,000
Net Amount Presented in the Consolidated Balance Sheets	[2]	84,000,000				84,000,000				111,000,000
Collateral Netting		39,000,000				39,000,000				64,000,000
Natural gas derivatives [Member] | Gains (Losses) in Revenue [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		7,000,000		5,000,000		49,000,000		(96,000,000)
Natural gas derivatives [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		1,000,000	[3]	4,000,000	[3]	(42,000,000)	[4]	114,000,000	[4]
Natural gas derivatives [Member] | Current Assets [Member]
Derivative, Fair Value, Net [Abstract]
Gross Amounts Recognized	[1]	74,000,000				74,000,000				115,000,000
Gross amounts offset		(10,000,000)				(10,000,000)				(16,000,000)
Derivative Asset	[2]	64,000,000				64,000,000				99,000,000
Natural gas derivatives [Member] | Other Assets [Member]
Derivative, Fair Value, Net [Abstract]
Gross Amounts Recognized	[1]	35,000,000				35,000,000				34,000,000
Gross amounts offset		(2,000,000)				(2,000,000)				(2,000,000)
Derivative Asset	[2]	33,000,000				33,000,000				32,000,000
Natural gas derivatives [Member] | Current Liabilities [Member]
Derivative, Fair Value, Net [Abstract]
Gross Amounts Recognized	[1]	(45,000,000)				(45,000,000)				(84,000,000)
Gross amounts offset		38,000,000				38,000,000				65,000,000
Derivative Liability	[2]	(7,000,000)				(7,000,000)				(19,000,000)
Natural gas derivatives [Member] | Other Liabilities [Member]
Derivative, Fair Value, Net [Abstract]
Gross Amounts Recognized	[1]	(19,000,000)				(19,000,000)				(18,000,000)
Gross amounts offset		13,000,000				13,000,000				17,000,000
Derivative Liability	[2]	(6,000,000)				(6,000,000)				(1,000,000)
Indexed debt securities derivative | Gains (losses) in Other Income (Expense) [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		(91,000,000)		(50,000,000)		(67,000,000)		(7,000,000)
Not Designated as Hedging Instrument [Member] | Natural gas derivatives [Member] | Current Assets [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Asset, Fair Value		66,000,000	[5],[6]			66,000,000	[5],[6]			101,000,000	[7],[8]
Indexed debt securities derivative		2,000,000	[5],[6]			2,000,000	[5],[6]			1,000,000	[7],[8]
Not Designated as Hedging Instrument [Member] | Natural gas derivatives [Member] | Other Assets [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Asset, Fair Value		33,000,000	[5],[6]			33,000,000	[5],[6]			32,000,000	[7],[8]
Indexed debt securities derivative		0	[5],[6]			0	[5],[6]			0	[7],[8]
Not Designated as Hedging Instrument [Member] | Natural gas derivatives [Member] | Current Liabilities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Asset, Fair Value		8,000,000	[5],[6]			8,000,000	[5],[6]			14,000,000	[7],[8]
Indexed debt securities derivative		43,000,000	[5],[6]			43,000,000	[5],[6]			83,000,000	[7],[8]
Not Designated as Hedging Instrument [Member] | Natural gas derivatives [Member] | Other Liabilities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Asset, Fair Value		2,000,000	[5],[6]			2,000,000	[5],[6]			2,000,000	[7],[8]
Indexed debt securities derivative		19,000,000	[5],[6]			19,000,000	[5],[6]			18,000,000	[7],[8]
Not Designated as Hedging Instrument [Member] | Indexed debt securities derivative | Current Liabilities [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative Asset, Fair Value		0				0				0
Indexed debt securities derivative		583,000,000				$ 583,000,000				$ 541,000,000
Long [Member] | Natural gas derivatives [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative, Nonmonetary Notional Amount, Volume | MMcf						77				60
Swap [Member] | Long [Member] | Natural gas derivatives [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract]
Derivative, Nonmonetary Notional Amount, Volume | MMcf						118				127
Enable Midstream Partners [Member] | Forward Contracts [Member] | Natural gas derivatives [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		$ 2,000,000
[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 Expenses: Natural Gas includes $-0- during each of the three months ended June 30, 2015 and 2014 related to physical forwards purchased from Enable.
[4]	The Gains (Losses) in Expenses: Natural Gas includes $-0- and $2 million during the six months ended June 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 $84 million asset as shown on CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above, offset by collateral netting of $39 million
[6]	The fair value shown for natural gas contracts is comprised of derivative gross volumes totaling 718 billion cubic feet (Bcf) or a net 77 Bcf long position. Of the net long position, basis swaps constitute 118 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 CenterPoint Energy’s Condensed Consolidated Balance Sheets (and as detailed in the table below), and was comprised of the natural gas contracts derivative assets and liabilities separately shown above, offset by collateral netting of $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			6 Months Ended
		Jun. 30, 2015USD ($)		Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)		Jun. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [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
Assets
Natural gas derivatives, netting adjustment		(12,000,000)	[1]		(12,000,000)	[1]		$ (18,000,000)	[2]
Total assets		1,087,000,000			1,087,000,000			1,117,000,000
Liabilities
Natural gas derivatives, netting adjustment		(51,000,000)	[1]		(51,000,000)	[1]		(82,000,000)	[2]
Total liabilities		596,000,000			596,000,000			561,000,000
Cash collateral posted with counterparties		39,000,000			39,000,000			64,000,000
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance		13,000,000		$ 1,000,000	17,000,000		$ 3,000,000
Total gains		0		2,000,000	0		0
Total settlements		(3,000,000)		1,000,000	(6,000,000)		2,000,000
Transfers into Level 3		0		0	0		(1,000,000)
Transfers out of Level 3		0		0	(1,000,000)		0
Ending balance (1)	[3]	10,000,000		4,000,000	10,000,000		4,000,000
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		0		$ 1,000,000	2,000,000		$ 2,000,000
Fair Value, Inputs, Level 1 [Member]
Assets
Total assets		992,000,000			992,000,000			993,000,000
Liabilities
Total liabilities		10,000,000			10,000,000			22,000,000
Fair Value, Inputs, Level 2 [Member]
Assets
Total assets		96,000,000			96,000,000			122,000,000
Liabilities
Total liabilities		636,000,000			636,000,000			618,000,000
Fair Value, Inputs, Level 3 [Member]
Assets
Total assets		11,000,000			11,000,000			20,000,000
Liabilities
Total liabilities		1,000,000			$ 1,000,000			3,000,000
Forward Contracts [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Fair Value Inputs, Price Per MMBtu					1.26
Forward Contracts [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Fair Value Inputs, Price Per MMBtu					3.79
Options Held [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Fair Value Assumptions, Expected Volatility Rate					0.00%
Options Held [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Fair Value Assumptions, Expected Volatility Rate					71.00%
Estimate of Fair Value Measurement [Member]
Estimated Fair Value of Financial Instruments
Notes Receivable, Fair Value Disclosure		363,000,000			$ 363,000,000			362,000,000
Long-term Debt		8,934,000,000			8,934,000,000			9,427,000,000
Reported Value Measurement [Member]
Estimated Fair Value of Financial Instruments
Notes Receivable, Fair Value Disclosure		363,000,000			363,000,000			363,000,000
Long-term Debt		8,392,000,000			8,392,000,000			8,652,000,000
Fair Value, Measurements, Recurring [Member]
Assets
Corporate equities		962,000,000			962,000,000			932,000,000
Investments, including money market funds (2)	[4]	28,000,000			28,000,000			54,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Corporate equities		962,000,000			962,000,000			932,000,000
Investments, including money market funds (2)	[4]	28,000,000			28,000,000			54,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Corporate equities		0			0			0
Investments, including money market funds (2)	[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 (2)	[4]	0			0			0
Fair Value, Measurements, Recurring [Member] | Natural gas derivatives [Member]
Assets
Natural gas derivatives, netting adjustment		(12,000,000)	[1]		(12,000,000)	[1]		(18,000,000)	[2]
Derivative Asset		97,000,000			97,000,000			131,000,000
Liabilities
Natural gas derivatives, netting adjustment		(51,000,000)	[1]		(51,000,000)	[1]		(82,000,000)	[2]
Derivative Liabilities		13,000,000			13,000,000			20,000,000
Fair Value, Measurements, Recurring [Member] | Natural gas derivatives [Member] | Fair Value, Inputs, Level 1 [Member]
Assets
Natural gas derivatives		2,000,000			2,000,000			7,000,000
Liabilities
Derivative Liability, Fair Value		10,000,000			10,000,000			22,000,000
Fair Value, Measurements, Recurring [Member] | Natural gas derivatives [Member] | Fair Value, Inputs, Level 2 [Member]
Assets
Natural gas derivatives		96,000,000			96,000,000			122,000,000
Liabilities
Derivative Liability, Fair Value		53,000,000			53,000,000			77,000,000
Fair Value, Measurements, Recurring [Member] | Natural gas derivatives [Member] | Fair Value, Inputs, Level 3 [Member]
Assets
Natural gas derivatives		11,000,000			11,000,000			20,000,000
Liabilities
Derivative Liability, Fair Value		1,000,000			1,000,000			3,000,000
Fair Value, Measurements, Recurring [Member] | IDS Derivative [Member]
Liabilities
Natural gas derivatives, netting adjustment		0	[1]		0	[1]		0	[2]
Derivative Liabilities		583,000,000			583,000,000			541,000,000
Fair Value, Measurements, Recurring [Member] | IDS Derivative [Member] | Fair Value, Inputs, Level 1 [Member]
Liabilities
Derivative Liability, Fair Value		0			0			0
Fair Value, Measurements, Recurring [Member] | IDS Derivative [Member] | Fair Value, Inputs, Level 2 [Member]
Liabilities
Derivative Liability, Fair Value		583,000,000			583,000,000			541,000,000
Fair Value, Measurements, Recurring [Member] | IDS Derivative [Member] | Fair Value, Inputs, Level 3 [Member]
Liabilities
Derivative Liability, Fair Value		$ 0			$ 0			$ 0
[1]	Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $39 million posted with the same counterparties.
[2]	Amounts represent the impact of legally enforceable master netting arrangements that allow CenterPoint Energy to settle positive and negative positions and also include cash collateral of $64 million posted with the same counterparties.
[3]	CenterPoint Energy did not have significant Level 3 purchases or sales during either of the three or six months ended June 30, 2015 or 2014.
[4]	Amounts are included in Prepaid Expenses and Other Current Assets in the Condensed Consolidated Balance Sheets.

Unconsolidated Affiliates (Deta

Unconsolidated Affiliates (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Jul. 31, 2015	Dec. 31, 2014	May. 30, 2014	Mar. 31, 2014
Publicly Traded Common Units, Percentage of Total Outstanding Units				7.00%
Investment in unconsolidated affiliates		$ 4,471		$ 4,471			$ 4,521
Southeast Supply Header LLC [Member]
Equity Method Investment, Ownership Percentage									25.05%
Equity Method Investment, Contributed Ownership Percentage		0.10%		0.10%				24.95%
Investment in unconsolidated affiliates	[1]	$ 0		$ 0			1
Enable Midstream Partners [Member]
Equity Method Investment, Ownership Percentage		55.40%		55.40%
Carrying value per unit of investment in Enable		$ 19.12		$ 19.12
Amount below carrying value		$ 734		$ 734
Investment in unconsolidated affiliates		$ 4,471		$ 4,471			4,520
Enable Midstream Partners [Member]
Enable's common unit price		$ 15.98		$ 15.98
Common Stock [Member] | Enable Midstream Partners [Member]
Equity Method Investment, Ownership, Shares		94,151,707		94,151,707
Subordinated Units [Member] | Enable Midstream Partners [Member]
Equity Method Investment, Ownership, Shares		139,704,916		139,704,916
Enable Midstream Partners [Member]
Indebtedness to CERC		$ 363		$ 363
Interest Income (Expense), Net		2	$ 2	4	$ 4
Interest Receivable		5		5			4
Enable Guaranteed Senior Notes [Member] | CERC Corp [Member]
Enable Senior Notes Due 2019 and 2024		1,100		1,100
Transitional Service [Member] | Enable Midstream Partners [Member]
Reimbursement for Transitional Services		2	37	7	82
Transitional Service cost receivable		4		4			28
Natural Gas Expenses [Member] | Enable Midstream Partners [Member]
Cost of natural gas purchases, affiliates		26	$ 27	65	$ 75
Due to Affiliate		7		7			$ 23
Subsequent Event [Member] | Enable Midstream Partners [Member]
Enable's common unit price						$ 16.36
Amount below carrying value						$ 645
Enable Midstream Partners [Member] | Enable Guaranteed Senior Notes [Member] | CERC Corp [Member]
Enable Senior Notes Due 2019 and 2024		$ 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				2.45%
[1]	CenterPoint Energy 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		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014	May. 30, 2014
Investment in unconsolidated affiliates		$ 4,471		$ 4,471		$ 4,521
Equity in earnings of unconsolidated affiliates, net		43	$ 71	95	$ 162
CenterPoint Energy’s ownership interest in Enable partners’ capital		4,817		4,817		4,869
CenterPoint Energy’s basis difference attributable to goodwill (1)	[1]	(217)		(217)		(217)
CenterPoint Energy’s accretable basis difference (2)	[2]	(129)		(129)		(132)
CenterPoint Energy’s total basis difference		(346)		(346)		(349)
CenterPoint Energy’s investment in Enable		4,471		4,471		4,520
Proceeds from Equity Method Investment, Dividends or Distributions		$ 73	94	$ 145	164
Southeast Supply Header LLC [Member]
Equity Method Investment, Contributed Ownership Percentage		0.10%		0.10%			24.95%
Investment in unconsolidated affiliates	[3]	$ 0		$ 0		1
Equity in earnings of unconsolidated affiliates, net	[3]	0	2	0	5
Proceeds from Equity Method Investment, Dividends or Distributions	[3]	0	4	0	7
Enable Midstream Partners [Member]
Investment in unconsolidated affiliates		4,471		4,471		4,520
Equity in earnings of unconsolidated affiliates, net		43	69	95	157
Operating revenues		590	826	1,206	1,828
Cost of sales, excluding depreciation and amortization		277	478	569	1,111
Operating income		93	139	197	301
Net income attributable to Enable		77	120	168	269
CenterPoint Energy’s interest		42	67	93	154
Basis difference accretion		1	2	2	3
CenterPoint Energy’s equity in earnings, net		43	69	95	157
Current assets		414		414		438
Non-current assets		11,766		11,766		11,399
Current liabilities		834		834		671
Non-current liabilities		2,611		2,611		2,343
Non-controlling interest		31		31		31
Enable partners’ capital		8,704		8,704		$ 8,792
Proceeds from Equity Method Investment, Dividends or Distributions		$ 73	$ 90	$ 145	$ 157
[1]	The difference relates to CenterPoint Energy’s proportionate share of Enable’s goodwill arising from its acquisition of Enogex LLC, and therefore will be recognized by CenterPoint Energy upon dilution or disposition of its interest in Enable.
[2]	The difference will be recognized by CenterPoint Energy over 30 years beginning May 1, 2013. CenterPoint Energy will also adjust the accretable basis difference for dilution or disposition of its interest in Enable.
[3]	CenterPoint Energy disposed of its remaining interest in SESH on June 30, 2015.

Goodwill (Details)

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

Capital Stock (Details)

Capital Stock (Details) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Capital stock shares authorized (in shares)	1,020,000,000
Common stock shares authorized (in shares)	1,000,000,000
Common stock shares par value (in dollars per share)	$ 0.01
Cumulative preferred stock shares authorized (in shares)	20,000,000
Cumulative preferred stock par value (in dollars per share)	$ 0.01
Total common stock issued (in shares)	430,260,023	429,795,996
Total common stock outstanding (in shares)	430,259,857	429,795,830
Treasury stock (in shares)	166	166

Indexed Debt Securities (ZENS43

Indexed Debt Securities (ZENS) and Securities Related to ZENS (Details) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Jun. 23, 2015$ / shares	May. 25, 2015
Realized loss on indexed debt securities	$ 7
Reduction In ZENS Derivative Obligation	18
Reduction In ZENS Debt	7
Subordinated Debt ZENS Member
Debt Instrument, Face Amount	1,000	$ 1,000
Long-term Debt, Gross	828	$ 828
Subordinated Note Cash Exchangeable Percentage Of Fair Value		95.00%
Contingent Principal Amount Outstanding	744	$ 744
AOL Common Member | Subordinated Debt ZENS Member
Share Price | $ / shares			$ 50
Proceeds from sale of AOL common stock	$ 32
Number Of Shares Referenced In Exchangeable Subordinated Note				0.045455
TW Common Member | Subordinated Debt ZENS Member
Number Of Shares Referenced In Exchangeable Subordinated Note	0.5	0.5		0.5
TWC Common Member | Subordinated Debt ZENS Member
Number Of Shares Referenced In Exchangeable Subordinated Note	0.125505	0.125505		0.125505
Time Common [Member] | Subordinated Debt ZENS Member
Number Of Shares Referenced In Exchangeable Subordinated Note	0.0625	0.0625		0.0625

Short-Term Borrowings and Lon44

Short-Term Borrowings and Long-term Debt (Details) - Debt Instrument, Name [Domain] $ in Millions	6 Months Ended
	Jun. 30, 2015USD ($)	Dec. 31, 2014USD ($)
Short-term Debt [Line Items]
Total short term borrowings	$ 24	$ 53
Credit Facilities [Abstract]
Total credit facility amount	2,100	2,100
Parent Company [Member]
Credit Facilities [Abstract]
Total credit facility amount	1,200	1,200
CenterPoint Houston [Member]
Credit Facilities [Abstract]
Total credit facility amount	300	300
CERC Corp [Member]
Credit Facilities [Abstract]
Total credit facility amount	600	600
Revolving Credit Facility [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	0	0
Revolving Credit Facility [Member] | Parent Company [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	0	0
Revolving Credit Facility [Member] | CenterPoint Houston [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	0	0
Revolving Credit Facility [Member] | CERC Corp [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	$ 0	0
Line of Credit [Member] | Parent Company [Member]
Credit Facilities [Abstract]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	65.00%
Percentage on limitation of debt to total capitalization under covenant amended (in hundredths)	70.00%
System restoration costs threshold for increase in permitted debt to EBITDA covenant ratio	$ 100
Consecutive Period for System Restoration Costs to Exceed $100 million (in months)	12
Line of Credit [Member] | Parent Company [Member] | London Interbank Offered Rate (LIBOR) [Member]
Credit Facilities [Abstract]
Basis Spread on LIBOR	1.25%
Line of Credit [Member] | CenterPoint Houston [Member]
Credit Facilities [Abstract]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	65.00%
Line of Credit [Member] | CenterPoint Houston [Member] | London Interbank Offered Rate (LIBOR) [Member]
Credit Facilities [Abstract]
Basis Spread on LIBOR	1.125%
Line of Credit [Member] | CERC Corp [Member]
Credit Facilities [Abstract]
Percentage on limitation of debt to total capitalization under covenant (in hundredths)	65.00%
Line of Credit [Member] | CERC Corp [Member] | London Interbank Offered Rate (LIBOR) [Member]
Credit Facilities [Abstract]
Basis Spread on LIBOR	1.50%
Letter of Credit [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	$ 10	10
Letter of Credit [Member] | Parent Company [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	6	6
Letter of Credit [Member] | CenterPoint Houston [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	4	4
Letter of Credit [Member] | CERC Corp [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	0	0
Commercial Paper [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	668	532
Commercial Paper [Member] | Parent Company [Member]
Credit Facilities [Abstract]
Total credit facility amount	1,000
Long-term Line of Credit	596	191
Commercial Paper [Member] | CenterPoint Houston [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	0	0
Commercial Paper [Member] | CERC Corp [Member]
Credit Facilities [Abstract]
Long-term Line of Credit	72	341
Product Financing Arrangement [Member]
Short-term Debt [Line Items]
Total short term borrowings	24	$ 53
Senior Notes Due Range 1 [Member] | Parent Company [Member]
Credit Facilities [Abstract]
Extinguishment of Debt, Amount	$ 200
Debt Instrument, Interest Rate, Stated Percentage	6.85%

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Effective Income Tax Rate Reconciliation, Percent	32.00%	37.00%	36.00%	37.00%

Commitments and Contingencies (

Commitments and Contingencies (Details) - Jun. 30, 2015 $ in Millions	USD ($)
GenOn Demand Charges Transportation Contracts [Member] | CERC Corp [Member]
Guarantees
Approximate amount of undiscounted maximum obligation under guarantee	$ 36
CenterPoint Midstream Guarantees [Member]
Guarantees
Approximate amount of undiscounted maximum obligation under guarantee	100
Enable Guaranteed Senior Notes [Member] | CERC Corp [Member]
Guarantees
Approximate amount of undiscounted maximum obligation under guarantee	1,100
Natural Gas Supply Commitments [Member]
Natural Gas Supply Commitments
2,015	228
2,016	485
2,017	471
2,018	419
2,019	227
After 2,019	$ 130
Gas Market Manipulation Cases [Member]
Legal Matters
Loss Contingency, Pending Claims, Number	1
Minnesota Service Territory [Member] | CERC Corp [Member]
Environmental Matters
Number of MGP sites in the Minnesota service territory (in number of sites)	7
Number of MGP sites in the Minnesota service territory where the company believes it has no liability (in number of sites)	2
Number of MGP sites where remediation is complete, other than ongoing operations (in number of sites)	2
Number of MGP sites in the Minnesota service territory where the company believes it has liability (in number of sites)	5
Liability recorded for remediation of Minnesota sites	$ 7
Minnesota Service Territory [Member] | CERC Corp [Member] | Minimum [Member]
Environmental Matters
Minimum estimated remediation costs for the Minnesota sites	$ 4
Years of remediation for the Minnesota sites (in years)	30
Minnesota Service Territory [Member] | CERC Corp [Member] | Maximum [Member]
Environmental Matters
Minimum estimated remediation costs for the Minnesota sites	$ 28
Years of remediation for the Minnesota sites (in years)	50

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net income	$ 77	$ 107	$ 208	$ 292
Basic weighted average shares outstanding	430,235,000	429,773,000	430,096,000	429,470,000
Plus: Incremental shares from assumed conversions:
Diluted weighted average shares	431,733,000	431,409,000	431,594,000	431,106,000
Basic earnings per share:
Net income	$ 0.18	$ 0.25	$ 0.48	$ 0.68
Diluted earnings per share:
Net income	$ 0.18	$ 0.25	$ 0.48	$ 0.68
Restricted Stock [Member]
Plus: Incremental shares from assumed conversions:
Incremental shares from assumed conversions	1,498,000	1,636,000	1,498,000	1,636,000

Reportable Business Segments (D

Reportable Business Segments (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues		$ 1,532	$ 1,884	$ 3,965	$ 5,047
Operating Income (Loss)		186	186	442	481
Assets		22,602		22,602		$ 23,200
Equity in earnings of unconsolidated affiliates, net		43	71	95	162
Investment in unconsolidated affiliates		4,471		4,471		4,521
Electric Transmission and Distribution [Member]
Segment Reporting Information [Line Items]
Revenues	[1]	705	698	1,317	1,327
Operating Income (Loss)		158	145	254	250
Electric Transmission and Distribution [Member] | Affiliates of NRG Energy, Inc. [Member]
Segment Reporting Information [Line Items]
Revenues		172	164	356	330
Electric Transmission and Distribution [Member] | Affiliates of Energy Future Holdings Corp. [Member]
Segment Reporting Information [Line Items]
Revenues		51	41	103	81
Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Revenues		420	526	1,605	2,004
Operating Income (Loss)		19	30	165	192
Energy Services [Member]
Segment Reporting Information [Line Items]
Revenues		404	657	1,036	1,709
Operating Income (Loss)		9	11	22	37
Midstream Investments [Member]
Segment Reporting Information [Line Items]
Revenues	[2]	0	0	0	0
Operating Income (Loss)	[2]	0	0	0	0
Other Operations [Member]
Segment Reporting Information [Line Items]
Revenues		3	3	7	7
Operating Income (Loss)		0	0	1	2
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues		(11)	(25)	(37)	(66)
Assets		(950)		(950)		(1,197)
Intersegment Eliminations [Member] | Electric Transmission and Distribution [Member]
Segment Reporting Information [Line Items]
Revenues		0	0	0	0
Intersegment Eliminations [Member] | Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Revenues		(7)	(6)	(15)	(15)
Intersegment Eliminations [Member] | Energy Services [Member]
Segment Reporting Information [Line Items]
Revenues		(4)	(19)	(22)	(51)
Intersegment Eliminations [Member] | Midstream Investments [Member]
Segment Reporting Information [Line Items]
Revenues	[2]	0	0	0	0
Intersegment Eliminations [Member] | Other Operations [Member]
Segment Reporting Information [Line Items]
Revenues		0	0	0	0
Operating Segments [Member] | Electric Transmission and Distribution [Member]
Segment Reporting Information [Line Items]
Assets		9,944		9,944		10,066
Operating Segments [Member] | Natural Gas Distribution [Member]
Segment Reporting Information [Line Items]
Assets		5,301		5,301		5,464
Operating Segments [Member] | Energy Services [Member]
Segment Reporting Information [Line Items]
Assets		837		837		978
Operating Segments [Member] | Midstream Investments [Member]
Segment Reporting Information [Line Items]
Assets	[2]	4,471		4,471		4,521
Operating Segments [Member] | Other Operations [Member]
Segment Reporting Information [Line Items]
Assets	[3]	2,999		2,999		3,368
Southeast Supply Header LLC [Member]
Segment Reporting Information [Line Items]
Equity in earnings of unconsolidated affiliates, net	[4]	0	2	0	5
Investment in unconsolidated affiliates	[4]	0		0		1
Southeast Supply Header LLC [Member] | Midstream Investments [Member]
Segment Reporting Information [Line Items]
Equity in earnings of unconsolidated affiliates, net		0	2	0	5
Investment in unconsolidated affiliates		0		0		1
Enable Midstream Partners [Member]
Segment Reporting Information [Line Items]
Equity in earnings of unconsolidated affiliates, net		43	69	95	157
Investment in unconsolidated affiliates		4,471		4,471		4,520
Enable Midstream Partners [Member] | Midstream Investments [Member]
Segment Reporting Information [Line Items]
Equity in earnings of unconsolidated affiliates, net		43	$ 69	95	$ 157
Investment in unconsolidated affiliates		4,471		4,471		4,520
Pension and Other Postretirement Plans Costs [Member] | Other Operations [Member]
Segment Reporting Information [Line Items]
Regulatory Assets		$ 757		$ 757		$ 795
[1]	(1)CenterPoint Houston’s transmission and distribution revenues from major customers are as follows (in millions): Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014Affiliates of NRG $172 $164 $356 $330 Affiliates of Energy Future Holdings Corp. $51 $41 $103 $81
[2]	(2)Midstream Investments’ equity earnings are as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 (in millions)Enable $43 $69 $95 $157SESH — 2 — 5 Total $43 $71 $95 $162Midstream Investments’ total assets are as follows: June 30, 2015 December 31, 2014 (in millions)Enable $4,471 $4,520SESH — 1 Total $4,471 $4,521
[3]	Included in total assets of Other Operations as of June 30, 2015 and December 31, 2014 are pension and other postemployment related regulatory assets of $757 million and $795 million, respectively.
[4]	CenterPoint Energy disposed of its remaining interest in SESH on June 30, 2015.

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 24, 2015	Jul. 22, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared			$ 0.2475	$ 0.2375	$ 0.4950	$ 0.4750
Proceeds from Equity Method Investment, Dividends or Distributions			$ 73	$ 94	$ 145	$ 164
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends Payable, Date Declared	Jul. 24, 2015
Common Stock, Dividends, Per Share, Declared	$ 0.2475
Dividends Payable, Date to be Paid, Day, Month and Year	Sep. 10, 2015
Dividends Payable, Date of Record, Day, Month and Year	Aug. 14, 2015
Enable Midstream Partners [Member]
Subsequent Event [Line Items]
Proceeds from Equity Method Investment, Dividends or Distributions			$ 73	$ 90	$ 145	$ 157
Enable Midstream Partners [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends Payable, Date Declared		Jul. 22, 2015
Common Stock, Dividends, Per Share, Declared		$ 0.316
Proceeds from Equity Method Investment, Dividends or Distributions		$ 74