Clearway Energy (CWEN.A) 10-Q 4 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 31, 2015
Class of Stock [Line Items]
Entity Registrant Name	NRG Yield LLC
Entity Central Index Key	1,637,757
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Common Class A [Member]
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		34,586,250
Common Class B [Member]
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		42,738,750
Common Class C [Member]
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		62,784,250
Common Class D [Member]
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		42,738,750

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	[1]	Sep. 30, 2015	Sep. 30, 2014	[1]
Operating Revenues
Total operating revenues	$ 209	$ 184		$ 606	$ 497
Operating Costs and Expenses [Abstract]
Cost of operations	69	60		211	173
Depreciation and amortization	50	34		163	112	[2]
General and administrative — affiliate	2	3		8	7
Acquisition-related transaction and integration costs	1	2		2	2
Total operating costs and expenses	122	99		384	294
Operating Income	87	85		222	203
Costs and Expenses [Abstract]
Equity in earnings of unconsolidated affiliates	19	11		29	26
Other income, net	1	1		2	2
Loss on debt extinguishment	(2)	0		(9)	0	[2]
Interest expense	(59)	(46)		(170)	(105)
Total other expense, net	(41)	(34)		(148)	(77)
Net Income	46	51	[3]	74	126	[2]
Less: Net (loss) income attributable to noncontrolling interests	(5)	0		2	0
Net Income (Loss) Attributable to NRG Yield LLC	$ 51	$ 51		$ 72	$ 126
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Condensed Consolidated Stateme3

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	[2]	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net Income	$ 46	$ 51	[1]	$ 74	$ 126	[1],[3]
Other Comprehensive Loss, net of tax
Unrealized (loss) gain on derivatives	(38)	4		(38)	(30)	[2]
Other comprehensive (loss) income	(38)	4		(38)	(30)	[2]
Comprehensive Income	8	55		36	96	[2]
Less: Comprehensive (loss) income attributable to noncontrolling interests	(5)	0		2	0	[2]
Comprehensive Income Attributable to NRG Yield LLC	$ 13	$ 55		$ 34	$ 96	[2]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents	$ 125	$ 406	[1]
Restricted cash	69	45	[1]
Accounts receivable — trade	104	85	[1]
Accounts receivable — affiliate	3	0	[1]
Inventory	30	27	[1]
Derivative instruments — affiliate	3	0	[1]
Notes receivable	7	6	[1]
Prepayments and other current assets	25	21	[1]
Total current assets	366	590	[1]
Property, plant and equipment
In service	4,929	4,796	[1]
Under construction	4	8	[1]
Total property, plant and equipment	4,933	4,804	[1]
Less accumulated depreciation	(499)	(338)	[1]
Net property, plant and equipment	4,434	4,466	[1]
Other Assets
Equity investments in affiliates	553	227	[1]
Notes receivable	11	15	[1]
Intangible assets, net of accumulated amortization of $80 and $36	1,377	1,423	[1]
Derivative instruments	0	2	[1]
Other non-current assets	103	103	[1]
Total other assets	2,044	1,770	[1]
Total Assets	6,844	6,826	[1]
Current Liabilities
Current portion of long-term debt — external	224	214	[1]
Accounts payable — trade	22	20	[1]
Accounts payable — affiliate	57	45	[1]
Derivative instruments	42	48	[1]
Accrued expenses and other current liabilities	79	61	[1]
Total current liabilities	424	388	[1]
Other Liabilities
Long-term debt — external	3,690	4,247	[1]
Long-term debt — affiliate	618	337	[1]
Derivative instruments	74	69	[1]
Other non-current liabilities	53	49	[1]
Total non-current liabilities	4,435	4,702	[1]
Total Liabilities	$ 4,859	$ 5,090	[1]
Commitments and Contingencies
Members' Equity
Contributed capital	$ 1,728	$ 1,609	[1]
Retained earnings	158	185	[1]
Accumulated other comprehensive loss	(96)	(58)	[1]
Noncontrolling interest	195	0	[1]
Total Members' Equity	1,985	1,736	[1]
Total Liabilities and Members’ Equity	$ 6,844	$ 6,826	[1]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Condensed Consolidated Balance5

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Intangible assets, accumulated amortization	$ 80	$ 36

Condensed Consolidated Stateme

Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2015		Sep. 30, 2014
Cash Flows from Operating Activities
Net income		$ 74		$ 126	[1],[2]
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Distributions in excess of equity in earnings of unconsolidated affiliates		25		17	[2]
Depreciation and amortization		163		112	[1],[2]
Amortization of financing costs and debt discount/premiums		5		3	[2]
Amortization of intangibles and out-of-market contracts		41		21	[2]
Adjustment for debt extinguishment		9		0	[1],[2]
Changes in derivative instruments		(36)		(14)	[2]
Changes in other working capital		(12)		(16)	[2]
Net Cash Provided by Operating Activities		269		249	[2]
Cash Flows from Investing Activities
Acquisition of businesses, net of cash acquired		(37)		(901)	[2]
Acquisition of Drop Down Assets, net of cash acquired		(489)		336	[2]
Capital expenditures		(16)		(28)	[2]
(Increase) decrease in restricted cash		(24)		20	[2]
Decrease in notes receivable		5		6	[2]
Proceeds from renewable energy grants		0		137	[2]
Net investments in unconsolidated affiliates		(335)		(17)	[2]
Other		0		11	[2]
Net Cash Used in Investing Activities		(896)		(1,108)	[2]
Cash Flows from Financing Activities
Contributions from noncontrolling interests		119		0	[2]
Capital contributions from NRG				2
Distributions and return of capital to NRG				(45)
Proceeds from the issuance of Class C and Class A units		599		630	[2]
Payment of distributions		(99)		(72)	[2]
Proceeds from issuance of long-term debt — external		302		579	[2]
Proceeds from issuance of long-term debt — affiliate		281		337	[2]
Payment of debt issuance costs		(7)		(18)	[2]
Payments for long-term debt — external		(849)		(220)	[2]
Net Cash Provided by Financing Activities		346		1,193	[2]
Net (Decrease) Increase in Cash and Cash Equivalents		(281)		334	[2]
Cash and Cash Equivalents at Beginning of Period		406	[3]	59	[2]
Cash and Cash Equivalents at End of Period		125		393	[2]
Affiliated Entity [Member]
Cash Flows from Financing Activities
Capital contributions from NRG		0		2	[2]
NRG [Member]
Cash Flows from Financing Activities
Distributions and return of capital to NRG		0
El Segundo [Member] | NRG [Member]
Cash Flows from Financing Activities
Distributions and return of capital to NRG	[2]			(45)
Drop-down Acquisition [Member]
Cash Flows from Investing Activities
Acquisition of businesses, net of cash acquired		(489)		$ (336)
Additional Paid-in Capital [Member]
Cash Flows from Financing Activities
Proceeds from the issuance of Class C and Class A units		$ 599
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Nature of Business

Nature of Business	9 Months Ended
	Sep. 30, 2015
Nature of Business Disclosure [Abstract]
Business Description and Basis of Presentation [Text Block]	Nature of Business NRG Yield LLC, together with its consolidated subsidiaries, or the Company, was formed by NRG Energy, Inc., or NRG, as a Delaware limited liability company on March 5, 2013, to serve as the primary vehicle through which NRG owns, operates and acquires contracted renewable and conventional generation and thermal infrastructure assets. NRG owns 100% of the Company's Class B units and Class D units and receives distributions through its ownership of these units. NRG Yield, Inc., or Yield, Inc., owns 100% of the Company's Class A units and Class C units. NRG Yield LLC, through its wholly owned subsidiary, NRG Yield Operating LLC, or Yield Operating LLC, holds a portfolio of renewable and conventional generation and thermal infrastructure assets, primarily located in the Northeast, Southwest and California regions of the U.S. On June 29, 2015, Yield, Inc. issued 28,198,000 shares of Class C common stock at a price of $22 per share. Net proceeds to Yield, Inc. from the sale of the Class C common stock were $599 million , net of underwriting discounts and commissions of $21 million . Yield, Inc. utilized the proceeds of the offering to acquire 28,198,000 Class C units of NRG Yield LLC, increasing its voting interest to 44.9% and its economic interest to 53.3% . Yield, Inc. consolidates the results of the Company through its controlling interest as sole managing member. The following table represents the structure of the Company as of September 30, 2015 : As of September 30, 2015 , the Company's operating assets are comprised of the following projects: Projects Percentage Ownership Net Capacity (MW) (a) Offtake Counterparty Expiration Conventional GenConn Middletown (b) 50 % 95 Connecticut Light & Power 2041 GenConn Devon (b) 50 % 95 Connecticut Light & Power 2040 Marsh Landing 100 % 720 Pacific Gas and Electric 2023 El Segundo 100 % 550 Southern California Edison 2023 Walnut Creek 100 % 485 Southern California Edison 2023 1,945 Utility Scale Solar Alpine 100 % 66 Pacific Gas and Electric 2033 Avenal (b) 50 % 23 Pacific Gas and Electric 2031 Avra Valley 100 % 25 Tucson Electric Power 2032 Blythe 100 % 21 Southern California Edison 2029 Borrego 100 % 26 San Diego Gas and Electric 2038 Roadrunner 100 % 20 El Paso Electric 2031 CVSR 48.95 % 122 Pacific Gas and Electric 2038 Kansas South 100 % 20 Pacific Gas and Electric 2033 TA High Desert 100 % 20 Southern California Edison 2033 Desert Sunlight 250 25 % 63 Southern California Edison 2035 Desert Sunlight 300 25 % 75 Pacific Gas and Electric 2040 481 Distributed Solar AZ DG Solar Projects 100 % 5 Various 2025 - 2033 PFMG DG Solar Projects 51 % 4 Various 2032 9 Wind Alta I 100 % 150 Southern California Edison 2035 Alta II 100 % 150 Southern California Edison 2035 Alta III 100 % 150 Southern California Edison 2035 Alta IV 100 % 102 Southern California Edison 2035 Alta V 100 % 168 Southern California Edison 2035 Alta X (c)(d) 100 % 137 Southern California Edison 2038 (c) Alta XI (c)(d) 100 % 90 Southern California Edison 2038 (c) South Trent 100 % 101 AEP Energy Partners 2029 Laredo Ridge 100 % 80 Nebraska Public Power District 2031 Taloga 100 % 130 Oklahoma Gas & Electric 2031 Pinnacle 100 % 55 Maryland Department of General Services and University System of Maryland 2031 Buffalo Bear 100 % 19 Western Farmers Electric Co-operative 2033 Spring Canyon II (c) 90.1 % 31 Platte River Power Authority 2038 Spring Canyon III (c) 90.1 % 26 Platte River Power Authority 2039 1,389 Thermal Thermal equivalent MWt (e) 100 % 1,310 Various Various Thermal generation 100 % 124 Various Various Total net capacity (excluding equivalent MWt) (f) 3,948 (a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015 . (b) On September 30, 2015, the Company acquired NRG's remaining 0.05% for an immaterial amount. (c) Projects are part of tax equity arrangements, as further described in Note 2, Summary of Significant Accounting Policies . (d) PPA begins on January 1, 2016. (e) For thermal energy, net capacity represents MWt for steam or chilled water and excludes 134 MWt available under the right-to-use provisions contained in agreements between two of the Company's thermal facilities and certain of its customers. (f) Total net capacity excludes capacity for RPV Holdco and DGPV Holdco, which are consolidated by NRG, as further described in Note 5, Variable Interest Entities . Substantially all of the Company's generation assets are under long-term contractual arrangements for the output or capacity from these assets. The thermal assets are comprised of district energy systems and combined heat and power plants that produce steam, hot water and/or chilled water and in some instances, electricity at a central plant. Three of the district energy systems are subject to rate regulation by state public utility commissions while the other district energy systems have rates determined by negotiated bilateral contracts. The Company entered into a management services agreement with NRG for various services, including human resources, accounting, tax, legal, information systems, treasury, and risk management. Costs incurred by the Company under this agreement were $8 million and $7 million for the nine months ended September 30, 2015 , and 2014 , respectively, which included certain direct expenses incurred by NRG on behalf of the Company. As described in Note 3 , Business Acquisitions , on January 2, 2015, the Company acquired the Laredo Ridge, Tapestry, and Walnut Creek projects, or the January 2015 Drop Down Assets, for total cash consideration of $489 million , including $9 million for working capital, plus assumed debt of $737 million . Additionally, on June 30, 2014, the Company acquired the TA High Desert, Kansas South, and El Segundo projects, or the June 2014 Drop Down Assets, from NRG for total cash consideration of $357 million plus assumed project level debt. These acquisitions were accounted for as transfers of entities under common control. The accounting guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its consolidated financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period or from the date the entities were under common control (if later than the beginning of the financial statements period). The January 2015 Drop Down Assets are reflected as if the transfer took place on April 1, 2014, which represents the date these entities were acquired by NRG. The accompanying unaudited interim consolidated financial statements have been prepared in accordance with the SEC’s regulations for interim financial information. Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. The following notes should be read in conjunction with the accounting policies and other disclosures as set forth in the notes to the Company's audited consolidated financial statements for the year ended December 31, 2014, included in the Company's Prospectus dated June 22, 2015. Interim results are not necessarily indicative of results for a full year. In the opinion of management, the accompanying unaudited interim consolidated financial statements contain all material adjustments consisting of normal and recurring accruals necessary to present fairly the Company's consolidated financial position as of September 30, 2015 , and the results of operations, comprehensive income and cash flows for the nine months ended September 30, 2015 , and 2014 .

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates The preparation of consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions. These estimates and assumptions impact the reported amount of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the consolidated financial statements. They also impact the reported amount of net earnings during the reporting period. Actual results could be different from these estimates. Tax Equity Arrangements Certain portions of the Company’s noncontrolling interests in subsidiaries represent third-party interests in the net assets under certain tax equity arrangements, which are consolidated by the Company, that have been entered into to finance the cost of wind facilities eligible for certain tax credits. Additionally, certain portions of the Company’s investments in unconsolidated affiliates reflect the Company’s interests in tax equity arrangements, that are not consolidated by the Company, that have been entered into to finance the cost of solar energy systems under operating leases eligible for certain tax credits. The Company has determined that the provisions in the contractual agreements of these structures represent substantive profit sharing arrangements. Further, the Company has determined that the appropriate methodology for calculating the noncontrolling interest and investment in unconsolidated affiliates that reflects the substantive profit sharing arrangements is a balance sheet approach utilizing the hypothetical liquidation at book value, or HLBV, method. Under the HLBV method, the amounts reported as noncontrolling interests and investment in unconsolidated affiliates represent the amounts the investors to the tax equity arrangements would hypothetically receive at each balance sheet date under the liquidation provisions of the contractual agreements, assuming the net assets of the funding structures were liquidated at their recorded amounts determined in accordance with U.S. GAAP. The investors’ interests in the results of operations of the funding structures are determined as the difference in noncontrolling interests and investment in unconsolidated affiliates at the start and end of each reporting period, after taking into account any capital transactions between the structures and the funds’ investors. The calculations utilized to apply the HLBV method include estimated calculations of taxable income or losses for each reporting period. Noncontrolling Interests The following table reflects the changes in the Company's noncontrolling interest balance: (In millions) Balance as of December 31, 2014 — Contributions from noncontrolling interest for Alta Wind X-X1 TE Holdco 119 Noncontrolling interest acquired in Spring Canyon acquisition 74 Comprehensive income 2 Balance as of September 30, 2015 $ 195 On June 30, 2015, Yield Operating LLC sold an economic interest in Alta Wind X-XI TE Holdco, holder of the Alta Wind X and Alta Wind XI projects, to a financial institution in order to monetize cash and tax attributes, primarily production tax credits. The net proceeds of $119 million are reflected as noncontrolling interest in the Company's balance sheet. As described in Note 3, Business Acquisitions , the Company acquired Spring Canyon on May 7, 2015. The Company owns 90.1% of the Class B shares of Spring Canyon. The seller, Invenergy, owns the remaining 9.9% of the Class B shares and the Class A shares are owned by a tax equity investor. The interests of Invenergy and the tax equity investor of $74 million are shown as noncontrolling interests. Distributions Third Quarter 2015 Second Quarter 2015 First Quarter 2015 Distributions per unit A, B $ 0.21 $ 0.20 $ 0.39 Distributions per unit C, D $ 0.21 $ 0.20 N/A On November 4, 2015 , the Company announced the declaration of a distribution on its Class A, Class B, Class C and Class D units of $0.215 per unit payable on December 15, 2015 to unit holders of record as of December 1, 2015 . Income Taxes The Company is classified as a partnership for federal and state income tax purposes. Therefore, federal and state income taxes are assessed at the partner level. Accordingly, no provision has been made for federal or state income taxes in the accompanying financial statements. Recent Accounting Developments ASU 2015-16 — In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments , or ASU No. 2015-16. The amendments of ASU No. 2015-16 require that an acquirer recognize measurement period adjustments to the provisional amounts recognized in a business combination in the reporting period during which the adjustments are determined. Additionally, the amendments of ASU No. 2015-16 require the acquirer to record in the same period's financial statements the effect on earnings of changes in depreciation, amortization or other income effects, if any, as a result of the measurement period adjustment, calculated as if the accounting had been completed at the acquisition date as well as disclosing on either the face of the income statement or in the notes the portion of the amount recorded in current period earnings that would have been recorded in previous reporting periods. The guidance in ASU No. 2015-16 is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The amendments should be applied prospectively. The adoption of this standard is not expected to have a material impact on the Company's results of operations, cash flows or financial position. ASU 2015-03 and ASU 2015-15 — In April 2015, the FASB issued ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs , or ASU No. 2015-03. The amendments of ASU No. 2015-03 were issued to reduce complexity in the balance sheet presentation of debt issuance costs. ASU No. 2015-03 requires that debt issuance costs be presented in the balance sheet as a direct deduction from the carrying amount of debt liability, consistent with debt discounts or premiums. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this standard. Additionally, in August 2015, the FASB issued ASU No. 2015-15, Interest - Imputation of Interest (Subtopic 835-30): Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements, or ASU No. 2015-15, as ASU No. 2015-03 did not specifically address presentation or subsequent measurement of debt issuance costs related to line-of-credit arrangements. ASU No. 2015-15 allows an entity to continue to defer and present debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. The guidance in ASU No. 2015-03 and ASU No. 2015-15 is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted for financial statements that have not been previously issued. Had the Company adopted this guidance early, other assets would have been lower by $ 54 million and $ 61 million with corresponding decreases in debt as of September 30, 2015 , and December 31, 2014 , respectively. The adoption of this standard will have no impact on the Company's results of operations, cash flows or net assets. ASU 2015-02 — In February 2015, the FASB issued ASU No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis , or ASU No. 2015-02. The amendments of ASU No. 2015-02 were issued in an effort to minimize situations under previously existing guidance in which a reporting entity was required to consolidate another legal entity in which that reporting entity did not have: (1) the ability through contractual rights to act primarily on its own behalf; (2) ownership of the majority of the legal entity's voting rights; or (3) the exposure to a majority of the legal entity's economic benefits. ASU No. 2015-02 affects reporting entities that are required to evaluate whether they should consolidate certain legal entities. All legal entities are subject to reevaluation under the revised consolidation model. The guidance in ASU No. 2015-02 is effective for periods beginning after December 15, 2015. Early adoption is permitted. The Company adopted the standard effective January 1, 2015 and the adoption of this standard did not impact the Company's results of operations, cash flows or financial position. ASU 2014-16 — In November 2014, the FASB issued ASU No. 2014-16, Derivatives and Hedging (Topic 815): Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity , or ASU No. 2014-16. The amendments of ASU No. 2014-16 clarify how U.S. GAAP should be applied in determining whether the nature of a host contract is more akin to debt or equity and in evaluating whether the economic characteristics and risks of an embedded feature are "clearly and closely related" to its host contract. The guidance in ASU No. 2014-16 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted. The Company adopted the standard effective January 1, 2015 and the adoption of this standard did not impact the Company's results of operations, cash flows or financial position. ASU 2014-09 — In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), or ASU No. 2014-09. The amendments of ASU No. 2014-09 complete the joint effort between the FASB and the International Accounting Standards Board, or IASB, to develop a common revenue standard for U.S. GAAP and International Financial Reporting Standards, or IFRS, and to improve financial reporting. The guidance in ASU No. 2014-09 provides that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for the goods or services provided and establishes the following steps to be applied by an entity: (1) identify the contract with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies the performance obligation. In August 2015, the FASB issued ASU 2015-14, which formally deferred the effective date by one year to make the guidance of ASU No. 2014-09 effective for annual reporting periods beginning after December 15, 2017, including interim periods therein. Early adoption is permitted, but not prior to the original effective date, which was for annual reporting periods beginning after December 15, 2016. The Company is currently evaluating the impact of the standard on the Company's results of operations, cash flows and financial position.

Business Acquisitions

Business Acquisitions	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Business Acquisition	Note 3 — Business Acquisitions 2015 Acquisitions November 2015 Drop Down Assets from NRG On November 3, 2015, the Company acquired 75% of the Class B interests of NRG Wind TE Holdco, or the November 2015 Drop Down Assets, which owns a portfolio of 12 wind facilities totaling 814 net MW, from NRG for total cash consideration of $210 million , subject to working capital adjustments. The Company will be responsible for its pro-rata share of non-recourse project debt of $193 million and noncontrolling interest associated with a tax equity structure of $165 million (as of September 30, 2015). The Company funded the acquisition with borrowings from the revolving credit facility. The assets and liabilities transferred to the Company relate to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50, Business Combinations - Related Issues . The difference between the cash paid and historical value of the entities' equity was recorded as a distribution to NRG and reduced the balance of its contributed capital. Because the transaction constituted a transfer of net assets under common control, the guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. The Class A interests of NRG Wind TE Holdco are owned by a tax equity investor, or Investor, who receives 99% of allocations of taxable income and other items until the flip point, which occurs when the Investor obtains a specified return on its initial investment, at which time the allocations to the Investor change to 8.53% . The Company generally receives 75% of cash available for distribution until the flip point, at which time the allocations to the Company of cash available for distribution change to 68.60% . If the flip point has not occurred by a specified date, 100% of cash available for distribution is allocated to the Investor until the flip point occurs. NRG Wind TE Holdco is a VIE and the Company is the primary beneficiary, through its position as managing member, and consolidates NRG Wind TE Holdco. The following is a summary of assets and liabilities transferred in connection with the acquisition as of September 30, 2015 : NRG Wind TE Holdco (In millions) Current assets $ 34 Property, plant and equipment 673 Non-current assets 179 Total assets 886 Debt 193 Other current and non-current liabilities 33 Total liabilities 226 Less: noncontrolling interest $ 289 Net assets acquired $ 371 Supplemental Pro Forma Information As described above, the Company's acquisition of the November 2015 Drop Down Assets was accounted for as a transfer of entities under common control. The following unaudited supplemental pro forma information represents the results of operations as if the Company had acquired the November 2015 Drop Down Assets on January 1, 2014, including the impact of acquisition accounting with respect to NRG's acquisition of the projects. For the three months ended For the nine months ended (In millions) September 30, 2015 September 30, 2014 September 30, 2015 September 30, 2014 Operating revenues $ 225 $ 200 $ 660 $ 561 Net income 35 48 57 96 Desert Sunlight — On June 29, 2015, the Company acquired 25% of the membership interest in Desert Sunlight Investment Holdings, LLC, which owns two solar photovoltaic facilities that total 550 MW, located in Desert Center, California from EFS Desert Sun, LLC, an affiliate of GE Energy Financial Services for a purchase price of $285 million . Power generated by the facilities is sold to Southern California Edison and Pacific Gas and Electric under long-term PPAs with approximately 20 years and 25 years of remaining contract life, respectively. The Company accounts for its 25% investment as an equity method investment. Spring Canyon — On May 7, 2015, the Company acquired a 90.1% interest in Spring Canyon II, a 34 MW wind facility, and Spring Canyon III, a 29 MW wind facility, each located in Logan County, Colorado, from Invenergy Wind Global LLC. The purchase price was funded with cash on hand. Power generated by Spring Canyon II and Spring Canyon III is sold to Platte River Power Authority under long-term PPAs with approximately 24 years of remaining contract life. University of Bridgeport Fuel Cell — On April 30, 2015, the Company completed the acquisition of the University of Bridgeport Fuel Cell project in Bridgeport, Connecticut from FuelCell Energy, Inc. The project added an additional 1.4 MW of thermal capacity to the Company's portfolio, with a 12 years contract, with the option for a 7-year extension. The acquisition is reflected in the Company's Thermal segment. January 2015 Drop Down Assets from NRG — On January 2, 2015, the Company acquired the following projects from NRG: (i) Laredo Ridge, an 80 MW wind facility located in Petersburg, Nebraska, (ii) Tapestry, which includes Buffalo Bear, a 19 MW wind facility in Buffalo, Oklahoma; Taloga, a 130 MW wind facility in Putnum, Oklahoma; and Pinnacle, a 55 MW wind facility in Keyser, West Virginia, and (iii) Walnut Creek, a 485 MW natural gas facility located in City of Industry, California, for total cash consideration of $489 million , including $9 million for working capital, plus assumed project-level debt of $737 million . The Company funded the acquisition with cash on hand and drawings under its revolving credit facility. The assets and liabilities transferred to the Company relate to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50, Business Combinations - Related Issues . The difference between the cash paid and the historical value of the entities' equity of $61 million , as well as $23 million of AOCL, was recorded as a distribution to NRG and reduced the balance of its contributed capital. Since the transaction constituted a transfer of assets under common control, the guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. NRG acquired the majority of EME's assets, including Laredo Ridge, Tapestry and Walnut Creek, on April 1, 2014. The following table presents the historical information summary combining the financial information for the January 2015 Drop Down Assets transferred in connection with the acquisition: December 31, 2014 As Previously Reported Walnut Creek Tapestry Laredo Ridge As Currently Reported (In millions) Current assets $ 523 $ 46 $ 14 $ 7 $ 590 Property, plant and equipment 3,487 575 286 118 4,466 Non-current assets 1,603 57 61 49 1,770 Total assets 5,613 678 361 174 6,826 Debt 4,061 437 192 108 4,798 Other current and non-current liabilities 221 62 5 4 292 Total liabilities 4,282 499 197 112 5,090 Net assets $ 1,331 $ 179 $ 164 $ 62 $ 1,736 Supplemental Pro Forma Information As described above, the Company's acquisition of the January 2015 Drop Down Assets was accounted for as a transfer of entities under common control and all periods were retrospectively adjusted to reflect the entities as if they were transferred on the date the entities were under common control, which was April 1, 2014, the date NRG acquired Walnut Creek, Laredo Ridge and Tapestry. The following unaudited supplemental pro forma information represents the results of operations as if the Company had acquired the January 2015 Drop Down Assets on January 1, 2014, including the impact of acquisition accounting with respect to NRG's acquisition of the projects. For the nine months ended (In millions) September 30, 2014 Operating revenues $ 523 Net income 122 Since the acquisition date, the January 2015 Drop Down Assets contributed $106 million in operating revenues and $31 million in net income. 2014 Acquisitions Alta Wind Portfolio Acquisition — On August 12, 2014, the Company acquired 100% of the membership interests of Alta Wind Asset Management Holdings, LLC, Alta Wind Company, LLC, Alta Wind X Holding Company, LLC and Alta Wind XI Holding Company, LLC, which collectively own seven wind facilities that total 947 MW located in Tehachapi, California and a portfolio of associated land leases, or the Alta Wind Portfolio. Power generated by the Alta Wind Portfolio is sold to Southern California Edison under long-term PPAs, with 21 years of remaining contract life for Alta Wind I-V. The Alta Wind X and XI PPAs begin in 2016 with a term of 22 years and currently sell energy and renewable energy credits on a merchant basis. The purchase price for the Alta Wind Portfolio was $923 million , which consisted of a base purchase price of $870 million , as well as a payment for working capital of $53 million , plus the assumption of $1.6 billion of non-recourse project-level debt. In order to fund the purchase price, Yield, Inc. completed an equity offering of 12,075,000 shares of its Class A common stock at an offering price of $54.00 per share on July 29, 2014, which resulted in net proceeds of $630 million , after underwriting discounts and expenses. In addition, on August 5, 2014, Yield Operating LLC issued $500 million of Senior Notes, which bear interest at a rate of 5.375% and mature in August 2024. The acquisition was recorded as a business combination under ASC 805-50, with identifiable assets acquired and liabilities assumed provisionally recorded at their estimated fair values on the acquisition date. The accounting for the business combination was completed as of August 11, 2015, at which point the fair values became final. The following table summarizes the provisional amounts recognized for assets acquired and liabilities assumed as of December 31, 2014, as well as adjustments made through August 11, 2015, when the allocation became final. The purchase price of $923 million was allocated as follows: Acquisition Date Fair Value at December 31, 2014 Measurement period adjustments Revised Acquisition Date (In millions) Assets Cash $ 22 $ — $ 22 Current and non-current assets 49 (2 ) 47 Property, plant and equipment 1,304 6 1,310 Intangible assets 1,177 (6 ) 1,171 Total assets acquired 2,552 (2 ) 2,550 Liabilities Debt 1,591 — 1,591 Current and non-current liabilities 38 (2 ) 36 Total liabilities assumed 1,629 (2 ) 1,627 Net assets acquired $ 923 $ — $ 923 Fair value measurements The fair values of the property, plant and equipment and intangible assets were measured primarily based on significant inputs that are not observable in the market and thus represent a Level 3 measurement as defined in ASC 820. Significant inputs were as follows: • Property, plant and equipment — The fair values were determined primarily based on an income method using discounted cash flows and validated using a cost approach based on the replacement cost of the assets less economic obsolescence. The income approach was applied by determining the enterprise value for each acquired entity and subtracting the fair value of the intangible assets and working capital to determine the implied value of the tangible fixed assets. This methodology was primarily relied upon as the forecasted cash flows incorporate the specific attributes of each asset including age, useful life, equipment condition and technology. The income approach also allows for an accurate reflection of current and expected market dynamics such as supply and demand and regulatory environment as of the acquisition date. • Intangible Assets - PPAs — The fair values of the PPAs acquired were determined utilizing a variation of the income approach where the incremental future cash flows resulting from the acquired PPAs compared to the cash flows based on current market prices were discounted to present value at a weighted average cost of capital reflective of a market participant. The values were corroborated with available market data. The PPA values will be amortized over the term of the PPAs, which approximate 22 years . • Intangible Assets - Leasehold rights — The fair values of the leasehold rights acquired, which represent the contractual right to receive royalty payments equal to a percentage of PPA revenue from certain projects, were determined utilizing the income approach. The values were corroborated with available market data. The leasehold rights values will be amortized over a period of 21 years , which is equal to the average term of the contracts. June 2014 Drop Down Assets — On June 30, 2014, the Company acquired from NRG: (i) El Segundo, a 550 MW fast-start, gas-fired facility located in Los Angeles County, California; (ii) TA High Desert, a 20 MW solar facility located in Los Angeles County, California; and (iii) Kansas South, a 20 MW solar facility located in Kings County, California. The Company paid total cash consideration of $357 million , which represents a base purchase price of $349 million and $8 million of working capital adjustments. In addition, the acquisition included the assumption of $612 million of project-level debt. The assets and liabilities transferred to the Company relate to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50. The difference between the cash proceeds and the historical value of the net assets was recorded as a distribution to NRG and reduced the balance of its contributed capital. Since the transaction constituted a transfer of entities under common control, the guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its consolidated financial statements to reflect the transfer as if it had taken place from the beginning of the financial statements period.

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment Disclosure	Property, Plant and Equipment The Company’s major classes of property, plant, and equipment were as follows: September 30, 2015 December 31, 2014 Depreciable Lives (In millions) Facilities and equipment $ 4,837 $ 4,709 2 - 40 Years Land and improvements 92 87 Construction in progress 4 8 Total property, plant and equipment 4,933 4,804 Accumulated depreciation (499 ) (338 ) Net property, plant and equipment $ 4,434 $ 4,466

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Investments Accounted for by the Equity Method and Variable Interest Entities	Variable Interest Entities, or VIEs Entity that is Consolidated Alta TE Holdco — On June 30, 2015, the Company sold an economic interest in Alta TE Holdco to a financial institution in order to monetize certain cash and tax attributes, primarily production tax credits. The financial institution, or Investor, receives 99% of allocations of taxable income and other items until the flip point, which occurs when the Investor obtains a specified return on its initial investment, at which time the allocations to the Investor change to 5% . The Company receives 100% of cash available for distribution in the first year and subsequently receives 94.34% until the flip point, at which time the allocations to the Company of cash available for distribution change to 97.12% , unless the flip point has not occurred by a specified date, which would result in 100% of cash available for distribution allocated to the Investor until the flip point occurs. Alta TE Holdco is a VIE and the Company is the primary beneficiary, through its position as managing member, and therefore consolidates Alta TE Holdco. The net proceeds of $119 million are reflected as noncontrolling interest in the Company's balance sheet. The summarized financial information for Alta TE Holdco consisted of the following: (In millions) September 30, 2015 Other current and non-current assets $ 20 Property, plant and equipment 490 Intangible assets 287 Total assets 797 Current and non-current liabilities 13 Total liabilities 13 Noncontrolling interest 124 Net assets less noncontrolling interests $ 660 Entities that are not Consolidated The Company has interests in entities that are considered VIEs under ASC 810, Consolidation , but for which it is not considered the primary beneficiary. The Company accounts for its interests in these entities under the equity method of accounting. NRG DGPV Holdco 1 LLC — On May 8, 2015, NRG Yield DGPV Holding LLC, a subsidiary of the Company and NRG Renew LLC, a subsidiary of NRG, entered into a partnership by forming NRG DGPV Holdco 1 LLC, or DGPV Holdco, the purpose of which is to own or purchase solar power generation projects and other ancillary related assets from NRG Renew LLC, via intermediate funds, including: (i) a tax equity-financed portfolio of 11 recently completed community solar projects representing approximately 11 MW with a weighted average remaining PPA term of 20 years ; and (ii) a tax equity financed portfolio of approximately 29 commercial photovoltaic systems representing approximately 89 MW. The following illustrates the structure of DGPV Holdco: As of September 30, 2015, the Company's investment in DGPV Holdco related to the recently completed community solar projects was $17 million . Additionally, as of September 30, 2015, the Company's investment related to the commercial photovoltaic systems was $11 million , $9 million of which remained payable at September 30, 2015. DGPV Holdco is considered a VIE under ASC 810, however the Company is not the primary beneficiary and will account for its investment under the equity method. The Company's maximum exposure to loss is limited to its equity investment, which was $28 million as of September 30, 2015 . NRG RPV Holdco 1 LLC — On April 9, 2015, NRG Yield RPV Holding LLC, a subsidiary of the Company and NRG Residential Solar Solutions LLC, a subsidiary of NRG, entered into a partnership by forming NRG RPV Holdco 1 LLC, or RPV Holdco, that will invest in and hold operating portfolios of residential solar assets developed by NRG Home Solar, a subsidiary of NRG, including: (i) an existing, unlevered portfolio of over 2,200 leases across nine states representing approximately 17 MW with a weighted average remaining lease term of approximately 17 years ; and (ii) a tax equity-financed portfolios of approximately 13,000 leases representing approximately 90 MW, with an average lease term for the existing and new leases of approximately 17 to 20 years . The following illustrates the structure of RPV Holdco: The Company invested $26 million in RPV Holdco in April 2015 related to the existing, unlevered portfolio of leases. The Company also invested $21 million of its $150 million commitment in the tax equity-financed portfolios through September 30, 2015 . The Company's maximum exposure will be limited to its equity investment. RPV Holdco is considered a VIE under ASC 810, however the Company is not the primary beneficiary, and will account for its investment under the equity method. The Company's maximum exposure to loss is limited to its equity investment, which was $47 million as of September 30, 2015 . GenConn Energy LLC — The Company has a 50% interest in GCE Holding LLC, the owner of GenConn, which owns and operates two 190 MW peaking generation facilities in Connecticut at the Devon and Middletown sites. Each of these facilities was constructed pursuant to a 30-year cost of service type contract with the Connecticut Light & Power Company. GenConn is considered a VIE under ASC 810, however the Company is not the primary beneficiary, and accounts for its investment under the equity method. Effective September 30, 2015, the Company increased its 49.95% ownership by acquiring an additional 0.05% membership interest from NRG, bringing its total ownership interest to 50% . The project was funded through equity contributions from the owners and non-recourse, project-level debt. As of September 30, 2015 , the Company's investment in GenConn was $110 million and its maximum exposure to loss is limited to its equity investment. Additionally, GenConn has a $237 million project note with an interest rate of 4.73% and a maturity date of July 2041, and a 5-year, $35 million working capital facility that matures in 2018, which can be used to issue letters of credit at an interest rate of 1.875% per annum. As of September 30, 2015 , $220 million was outstanding under the note and nothing was drawn on the working capital facility. The note is secured by all of the GenConn assets. The following table presents summarized financial information for GCE Holding LLC: Three months ended September 30, Nine months ended September 30, (In millions) 2015 2014 2015 2014 Income Statement Data: Operating revenues $ 21 $ 18 $ 61 $ 62 Operating income 9 10 29 30 Net income $ 6 $ 7 $ 20 $ 21 September 30, 2015 December 31, 2014 Balance Sheet Data: (In millions) Current assets $ 32 $ 33 Non-current assets 420 438 Current liabilities 16 20 Non-current liabilities $ 216 $ 223 Desert Sunlight Investment Holdings, LLC - The Company has a 25% membership interest in Desert Sunlight Investment Holdings, LLC, which owns two solar photovoltaic facilities that total 550 MW in Desert Center, California. Power generated by the facilities is sold to Southern California Edison and Pacific Gas and Electric under long-term PPAs with approximately 20 years and 25 years of contract life, respectively. Desert Sunlight is considered a VIE under ASC 810, however the Company is not the primary beneficiary, and accounts for its investment under the equity method. As of September 30, 2015 , the Company's investment in Desert Sunlight was $281 million and its maximum exposure to loss is limited to its equity investment. The following tables present summarized financial information for Desert Sunlight Investment Holdings, LLC: Three months ended September 30, Nine months ended September 30, (In millions) 2015 2014 2015 2014 Income Statement Data: Operating revenues $ 73 $ 48 $ 170 $ 102 Operating income 51 33 108 58 Net income $ 39 $ 22 $ 70 $ 27 September 30, 2015 December 31, 2014 Balance Sheet Data: (In millions) Current assets $ 381 $ 706 Non-current assets 1,508 1,519 Current liabilities 91 436 Non-current liabilities $ 1,141 $ 1,152

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The Company records its derivative assets and liabilities at fair market value on its consolidated balance sheet. The following table presents assets and liabilities measured and recorded at fair value on the Company's consolidated balance sheets on a recurring basis and their level within the fair value hierarchy: As of September 30, 2015 As of December 31, 2014 Fair Value (a) Fair Value (a) Fair Value (b) (In millions) Level 1 Level 2 Level 2 Derivative assets: Commodity contracts $ — $ 3 $ — Interest rate contracts — — 2 Total assets — 3 2 Derivative liabilities: Commodity contracts 1 2 3 Interest rate contracts — 113 114 Total liabilities $ 1 $ 115 $ 117
Fair Value of Financial Instruments	Fair Value of Financial Instruments For cash and cash equivalents, restricted cash, accounts receivable, accounts payable, accounts payable — affiliate, accrued expenses and other liabilities, the carrying amounts approximate fair value because of the short-term maturity of those instruments and are classified as Level 1 within the fair value hierarchy. The estimated carrying amounts and fair values of the Company’s recorded financial instruments not carried at fair market value are as follows: As of September 30, 2015 As of December 31, 2014 Carrying Amount Fair Value Carrying Amount Fair Value (In millions) Assets: Notes receivable, including current portion $ 18 $ 18 $ 21 $ 21 Liabilities: Long-term debt — affiliate 618 542 337 386 Long-term debt — external, including current portion $ 3,914 $ 3,852 $ 4,461 $ 4,478 The fair value of notes receivable and long-term debt are based on expected future cash flows discounted at market interest rates, or current interest rates for similar instruments, and are classified as Level 3 within the fair value hierarchy. Fair Value Accounting under ASC 820 ASC 820 establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three levels as follows: • Level 1—quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access as of the measurement date. • Level 2—inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data. • Level 3—unobservable inputs for the asset or liability only used when there is little, if any, market activity for the asset or liability at the measurement date. In accordance with ASC 820, the Company determines the level in the fair value hierarchy within which each fair value measurement in its entirety falls, based on the lowest level input that is significant to the fair value measurement. Recurring Fair Value Measurements The Company records its derivative assets and liabilities at fair market value on its consolidated balance sheet. The following table presents assets and liabilities measured and recorded at fair value on the Company's consolidated balance sheets on a recurring basis and their level within the fair value hierarchy: As of September 30, 2015 As of December 31, 2014 Fair Value (a) Fair Value (a) Fair Value (b) (In millions) Level 1 Level 2 Level 2 Derivative assets: Commodity contracts $ — $ 3 $ — Interest rate contracts — — 2 Total assets — 3 2 Derivative liabilities: Commodity contracts 1 2 3 Interest rate contracts — 113 114 Total liabilities $ 1 $ 115 $ 117 (a) There were no assets or liabilities classified as Level 3 as of September 30, 2015 . (b) There were no assets or liabilities classified as Level 1 or Level 3 as of December 31, 2014 . Derivative Fair Value Measurements A portion of the Company's contracts are exchange-traded contracts with readily available quoted market prices. A majority of the Company's contracts are non-exchange-traded and valued using prices provided by external sources. For the Company’s energy markets, management receives quotes from multiple sources. To the extent that multiple quotes are received, the prices reflect the average of the bid-ask mid-point prices obtained from all sources believed to provide the most liquid market for the commodity. The remainder of the assets and liabilities represent contracts for which external sources or observable market quotes are not available. These contracts are valued using various valuation techniques including, but not limited to, internal models that apply fundamental analysis of the market and corroboration with similar markets. As of September 30, 2015 , there were no contracts valued with prices provided by models and other valuation techniques. The fair value of each contract is discounted using a risk free interest rate. In addition, a credit reserve is applied to reflect credit risk, which is calculated based on credit default swaps. To the extent that the net exposure is an asset, the Company uses the counterparty’s default swap rate. If the net exposure is a liability, the Company uses its default swap rate. The credit reserve is added to the discounted fair value to reflect the exit price that a market participant would be willing to receive to assume the liabilities or that a market participant would be willing to pay for the assets. As of September 30, 2015 , the credit reserve resulted in a $3 million increase in fair value in OCI. It is possible that future market prices could vary from those used in recording assets and liabilities and such variations could be material. Concentration of Credit Risk Credit risk relates to the risk of loss resulting from non-performance or non-payment by counterparties pursuant to the terms of their contractual obligations. The Company monitors and manages credit risk through credit policies that include: (i) an established credit approval process; (ii) daily monitoring of counterparties' credit limits; (iii) the use of credit mitigation measures such as margin, collateral, prepayment arrangements, or volumetric limits; (iv) the use of payment netting agreements; and (v) the use of master netting agreements that allow for the netting of positive and negative exposures of various contracts associated with a single counterparty. Risks surrounding counterparty performance and credit could ultimately impact the amount and timing of expected cash flows. The Company seeks to mitigate counterparty risk by having a diversified portfolio of counterparties. Counterparty credit exposure includes credit risk exposure under certain long-term agreements, including solar and other PPAs. As external sources or observable market quotes are not available to estimate such exposure, the Company estimates the exposure related to these contracts based on various techniques including, but not limited to, internal models based on a fundamental analysis of the market and extrapolation of observable market data with similar characteristics. Based on these valuation techniques, as of September 30, 2015 , credit risk exposure to these counterparties attributable to the Company's ownership interests was approximately $2.9 billion for the next five years . The majority of these power contracts are with utilities with strong credit quality and public utility commission or other regulatory support. However, such regulated utility counterparties can be impacted by changes in government regulations, which the Company is unable to predict.

Accounting for Derivative Instr

Accounting for Derivative Instruments and Hedging Activities (Notes)	9 Months Ended
	Sep. 30, 2015
Accounting for Derivative Instruments and Hedging Activities Disclosure [Abstract]
Accounting for Derivative Instruments and Hedging Activities	Accounting for Derivative Instruments and Hedging Activities This footnote should be read in conjunction with the complete description under Note 7, Accounting for Derivative Instruments and Hedging Activities , to the Company's audited consolidated financial statements for the year ended December 31, 2014, included in the Company's Prospectus dated June 22, 2015. Energy-Related Commodities As of September 30, 2015 , the Company had forward contracts with an NRG subsidiary, hedging the sale of power from the Alta X and Alta XI wind facilities, entered into in the first quarter of 2015 and extending through the end of 2015 and forward contracts for the purchase of fuel commodities relating to the forecasted usage of the Company’s district energy centers extending through 2017. At September 30, 2015 , these contracts were not designated as cash flow or fair value hedges. Interest Rate Swaps As of September 30, 2015 , the Company had interest rate derivative instruments on non-recourse debt extending through 2031, most of which are designated as cash flow hedges. Volumetric Underlying Derivative Transactions The following table summarizes the net notional volume buy/(sell) of the Company's open derivative transactions broken out by commodity as of September 30, 2015 , and December 31, 2014 . Total Volume September 30, 2015 December 31, 2014 Commodity Units (In millions) Natural Gas MMBtu 4 2 Interest Dollars $ 1,786 $ 2,817 The decrease in the interest rate position is primarily the result of settling the Alta X and Alta XI interest rate swaps in connection with the repayment of the outstanding project-level debt during the second quarter of 2015, as further described in Note 8, Long-term Debt . Fair Value of Derivative Instruments The following table summarizes the fair value within the derivative instrument valuation on the balance sheet: Fair Value Derivative Assets Derivative Liabilities September 30, 2015 December 31, 2014 September 30, 2015 December 31, 2014 (In millions) Derivatives Designated as Cash Flow Hedges: Interest rate contracts current $ — $ — $ 36 $ 40 Interest rate contracts long-term — 2 67 49 Total Derivatives Designated as Cash Flow Hedges — 2 103 89 Derivatives Not Designated as Cash Flow Hedges : Interest rate contracts current — — 3 5 Interest rate contracts long-term — — 7 20 Commodity contracts current 3 — 3 3 Total Derivatives Not Designated as Cash Flow Hedges 3 — 13 28 Total Derivatives $ 3 $ 2 $ 116 $ 117 The Company has elected to present derivative assets and liabilities on the balance sheet on a trade-by-trade basis and does not offset amounts at the counterparty master agreement level. As of September 30, 2015 , there was no outstanding collateral paid or received. The following table summarizes the offsetting of derivatives by counterparty master agreement level: Gross Amounts Not Offset in the Statement of Financial Position As of September 30, 2015 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts: (In millions) Derivative assets $ 3 $ (1 ) $ 2 Derivative liabilities (3 ) 1 (2 ) Total commodity contracts — — — Interest rate contracts: Derivative liabilities (113 ) — (113 ) Total interest rate contracts (113 ) — (113 ) Total derivative instruments $ (113 ) $ — $ (113 ) Gross Amounts Not Offset in the Statement of Financial Position As of December 31, 2014 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts: (In millions) Derivative liabilities $ (3 ) $ — $ (3 ) Total commodity contracts (3 ) — (3 ) Interest rate contracts: Derivative assets 2 (2 ) — Derivative liabilities (114 ) 2 (112 ) Total interest rate contracts (112 ) — (112 ) Total derivative instruments $ (115 ) $ — $ (115 ) Accumulated Other Comprehensive Loss The following table summarizes the effects on the Company’s accumulated OCL balance attributable to interest rate swaps designated as cash flow hedge derivatives: Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 (In millions) Accumulated OCL beginning balance $ (58 ) $ (35 ) $ (58 ) $ (1 ) Reclassified from accumulated OCL to income due to realization of previously deferred amounts 4 3 11 10 Mark-to-market of cash flow hedge accounting contracts (42 ) 1 (49 ) (40 ) Accumulated OCL ending balance $ (96 ) $ (31 ) $ (96 ) $ (31 ) Losses expected to be realized from OCL during the next 12 months $ (18 ) $ (18 ) Amounts reclassified from accumulated OCL into income and amounts recognized in income from the ineffective portion of cash flow hedges are recorded to interest expense. There was no ineffectiveness for the three or nine months ended September 30, 2015 , and 2014 . Impact of Derivative Instruments on the Statements of Operations The Company has interest rate derivative instruments that are not designated as cash flow hedges. The effect of interest rate hedges is recorded to interest expense. For the three months ended September 30, 2015 , and 2014 , the impact to the consolidated statements of operations was a loss of $6 million and $0 million , respectively. For the nine months ended September 30, 2015 , and 2014 , the impact to the consolidated statements of operations was a gain of $13 million and a loss of $6 million , respectively. A portion of the Company’s derivative commodity contracts relates to its Thermal Business for the purchase of fuel commodities based on the forecasted usage of the thermal district energy centers. Realized gains and losses on these contracts are reflected in the fuel costs that are permitted to be billed to customers through the related customer contracts or tariffs and, accordingly, no gains or losses are reflected in the consolidated statements of operations for these contracts. Commodity contracts also hedge the forecasted sale of power for the Alta X and Alta XI wind facilities until the start of the PPAs on January 1, 2016. The effect of these commodity hedges is recorded to operating revenues. For the three months ended September 30, 2015 , the impact to the consolidated statements of operations was an unrealized loss of $1 million . For the nine months ended September 30, 2015 , the impact to the consolidated statements of operations was an unrealized gain of $2 million . See Note 6 , Fair Value of Financial Instruments , for discussion regarding concentration of credit risk.

Long-term Debt

Long-term Debt	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Long-term Debt	Long-term Debt This footnote should be read in conjunction with the complete description under Note 9, Long-term Debt , to the Company's audited consolidated financial statements for the year ended December 31, 2014, included in the Company's Prospectus dated June 22, 2015. Long-term debt consisted of the following: September 30, 2015 December 31, 2014 September 30, 2015, interest rate % (a) (In millions, except rates) Senior Notes, due 2024 $ 500 $ 500 5.375 Long-term debt - affiliate, due 2019 337 337 3.580 Long-term debt - affiliate, due 2020 281 — 3.325 NRG Yield LLC and NRG Yield Operating LLC Revolving Credit Facility, due 2019 (b) 92 — L+2.75 Project-level debt: Alta Wind I, lease financing arrangement, due 2034 255 261 7.015 Alta Wind II, lease financing arrangement, due 2034 200 205 5.696 Alta Wind III, lease financing arrangement, due 2034 208 212 6.067 Alta Wind IV, lease financing arrangement, due 2034 135 138 5.938 Alta Wind V, lease financing arrangement, due 2035 215 220 6.071 Alta Wind X, due 2021 — 300 L+2.00 Alta Wind XI, due 2021 — 191 L+2.00 Alta Realty Investments, due 2031 33 34 7.00 Alta Wind Asset Management, due 2031 19 20 L+2.375 NRG West Holdings LLC, due 2023 (El Segundo Energy Center) 485 506 L+1.625 - L+2.25 NRG Marsh Landing LLC, due 2017 and 2023 431 464 L+1.75 - L+1.875 Walnut Creek Energy, due 2023 363 391 L+1.625 Tapestry Wind LLC, due 2021 184 192 L+1.625 NRG Solar Alpine LLC, due 2014 and 2022 156 163 L+1.75 NRG Energy Center Minneapolis LLC, due 2017 and 2025 110 121 5.95 -7.25 Laredo Ridge LLC, due 2028 105 108 L+1.875 NRG Solar Borrego LLC, due 2025 and 2038 73 75 L+ 2.50/5.65 South Trent Wind LLC, due 2020 62 65 L+1.625 NRG Solar Avra Valley LLC, due 2031 61 63 L+1.75 TA High Desert LLC, due 2020 and 2032 54 55 L+2.50/5.15 WCEP Holdings LLC, due 2023 46 46 L+3.00 NRG Roadrunner LLC, due 2031 40 42 L+1.625 NRG Solar Kansas South LLC, due 2031 34 35 L+2.00 NRG Solar Blythe LLC, due 2028 22 22 L+1.625 PFMG and related subsidiaries financing agreement, due 2030 30 31 6.00 NRG Energy Center Princeton LLC, due 2017 1 1 5.95 Subtotal project-level debt: 3,322 3,961 Total debt 4,532 4,798 Less current maturities 224 214 Total long-term debt $ 4,308 $ 4,584 (a) As of September 30, 2015 , L+ equals 3 month LIBOR plus x%, except for the NRG Marsh Landing term loan, Walnut Creek term loan, and the Revolving Credit Facility where L+ equals 1 month LIBOR plus x% and Kansas South where L+ equals 6 month LIBOR plus x%. (b) Applicable rate is determined by the Borrower Leverage Ratio, as defined in the credit agreement. The financing arrangements listed above contain certain covenants, including financial covenants that the Company is required to comply with during the term of the respective arrangement. As of September 30, 2015 , the Company was in compliance with all of the required covenants. The discussion below lists changes to or additions of long-term debt for the nine months ended September 30, 2015 . NRG Yield LLC and NRG Yield Operating LLC Revolving Credit Facility On June 26, 2015, the Company amended the revolving credit facility to, among other things, increase the availability from $450 million to $495 million . As of September 30, 2015 , $92 million of borrowings and $25 million of letters of credit were outstanding. On November 3, 2015, the Company borrowed $209 million from the revolving credit facility to finance the acquisition of the November 2015 Drop Down Assets as discussed in Note 3 , Business Acquisitions . Yield, Inc. 2020 Convertible Notes and Related Intercompany Note On June 29, 2015, Yield, Inc. closed on its offering of $287.5 million aggregate principal amount of 3.25% Convertible Notes due 2020, or the 2020 Convertible Notes. The 2020 Convertible Notes are convertible, under certain circumstances, into Yield, Inc.’s Class C common stock, cash or a combination thereof at an initial conversion price of $27.50 per Class C common share, which is equivalent to an initial conversion rate of approximately 36.3636 shares of Class C common stock per $1,000 principal amount of 2020 Convertible Notes. The Company and Yield Operating LLC provided a guarantee to Yield, Inc. with respect to the 2020 Convertible Notes. In addition, Yield Operating LLC and Yield, Inc. entered into an intercompany borrowing arrangement, under which Yield Operating LLC received $281 million of the proceeds of the 2020 Convertible Notes. The intercompany note bears interest at a rate of 3.325% and matures in 2020. Alta Wind X and Alta Wind XI Financing Due 2021 On June 30, 2015, Yield Operating LLC entered into a tax equity financing arrangement through which it has received $119 million in net proceeds, as described in Note 5 , Variable Interest Entities, or VIEs . These proceeds, as well as proceeds obtained from the June 29, 2015, Yield, Inc. common stock issuance, as described in Note 1, Nature of Business , and 2020 Convertible Notes issuance, as described above, were utilized to repay all of the outstanding project indebtedness associated with the Alta Wind X and Alta Wind XI wind facilities. The Company also settled interest rate swaps associated with the project level debt for the Alta Wind X and Alta Wind XI wind facilities at a value of $17 million . Laredo Ridge On July 27, 2010, Laredo Ridge entered into a credit agreement with a group of lenders for a $75 million construction loan that was convertible to a term loan upon completion of the project, a $53 million cash grant loan and a $3 million working capital loan facility. The project met the conditions to convert to a term loan on March 18, 2011. The cash grant loan was repaid in July 2011 with proceeds of the cash grant. The credit agreement also included a letter of credit facility on behalf of Laredo Ridge of up to $9 million . Laredo Ridge paid a fee equal to the applicable margin on issued letters of credit. On December 17, 2014, Laredo Ridge amended the credit agreement to increase its term loan borrowings by an additional $41 million to reduce the working capital facility by $1 million , to increase the letter of credit facility by $1 million and to reduce the related interest rate to LIBOR plus 1.875% through December 31, 2018, LIBOR plus 2.125% from January 1, 2019 through December 31, 2023 and LIBOR plus 2.375% from January 1, 2024 through the maturity date. The fee on the working capital facility was reduced to 0.5% . In addition, the maturity date was extended to December 31, 2028. The proceeds were utilized to make a distribution of $33 million to NRG Wind LLC, an NRG subsidiary, with the remaining $8 million utilized to fund the costs of the amendment. As of September 30, 2015 , $105 million was outstanding under the term loan, nothing was outstanding under the working capital facility, and $10 million of letters of credit in support of the project were issued. In connection with the amendment to the credit agreement, Laredo Ridge entered into a series of fixed for floating interest rate swaps that would fix the interest rate for a minimum of 75% of the outstanding notional amount. Laredo Ridge pays its counterparty the equivalent of a 2.31% fixed interest payment on a predetermined notional value, and quarterly, Laredo Ridge will receive the equivalent of a floating interest payment based on the three-month LIBOR calculated on the same notional value through December 31, 2028. All interest rate swap payments by Laredo Ridge and its counterparties are made quarterly and LIBOR is determined in advance of each interest period. Tapestry Wind LLC On December 21, 2011, Tapestry Wind LLC entered into a credit agreement with a group of lenders for a $214 million term loan and an $8 million working capital loan facility. The term loan matures in December 2021. It is secured by Tapestry Wind LLC's interest in the Buffalo Bear, Taloga, and Pinnacle projects. The term loan amortizes based upon a predetermined schedule. The working capital facility is available to fund the operating needs of Tapestry Wind LLC. The commitment fee on this facility is 0.75% . The credit agreement also includes a letter of credit facility on behalf of Tapestry Wind LLC of up to $20 million . Tapestry Wind LLC pays a fee equal to the applicable margin on issued letters of credit. Under the terms of the agreement, Tapestry Wind LLC entered into a series of fixed for floating interest rate swaps that would fix the interest rate for a minimum of 90% of the outstanding notional amount. Tapestry Wind LLC will pay its counterparty the equivalent of a 2.21% fixed interest payment on a predetermined notional value, and quarterly, Tapestry Wind LLC will receive the equivalent of a floating interest payment based on a three-month LIBOR calculated on the same notional value through December 21, 2021. All interest rate swap payments by Tapestry Wind LLC and its counterparties are made quarterly and the LIBOR is determined in advance of each interest period. Swaps became effective December 30, 2011, and amortize in proportion to the term loan. At the same time Tapestry Wind LLC entered into a series of forward starting swaps to hedge the refinancing risk. The swaps are effective December 21, 2021. Tapestry Wind LLC will pay its counterparty the equivalent of a 3.57% fixed interest payment on a predetermined notional value, and quarterly, Tapestry Wind LLC will receive the equivalent of a floating interest payment based on a three-month LIBOR calculated on the same notional value through December 21, 2029. On November 12, 2014, Tapestry Wind LLC amended the credit agreement to reduce the related interest rate to LIBOR plus 1.625% through December 20, 2018, and LIBOR plus 1.75% from December 21, 2018, through the maturity date. As of September 30, 2015 , $184 million was outstanding under the term loan, nothing was outstanding under the working capital facility and $20 million of letters of credit in support of the project were issued. Walnut Creek On July 27, 2011, Walnut Creek entered into a credit agreement with a group of lenders for a $442 million construction loan that was convertible to a term loan upon completion of the project, and a $5 million working capital loan facility. The project met the conditions to convert to a term loan on June 21, 2013, and matures in May 2023. The term loan amortizes based upon a predetermined schedule. The working capital facility is available to fund the operating needs of Walnut Creek. The commitment fee on this facility is 0.625% . The Walnut Creek agreement also includes a letter of credit facility on behalf of Walnut Creek of up to $117 million . Walnut Creek pays a fee equal to the applicable margin on issued letters of credit. Under the terms of the agreement, Walnut Creek entered into a series of fixed for floating interest rate swaps that would fix the interest rate for a minimum of 90% of the outstanding notional amount. Walnut Creek will pay its counterparty the equivalent of a 3.54% fixed interest payment on a predetermined notional value, and quarterly, Walnut Creek will receive the equivalent of a floating interest payment based on a three-month LIBOR calculated on the same notional value through May 31, 2023. All interest rate swap payments by Walnut Creek and its counterparties are made quarterly and the LIBOR is determined in advance of each interest period. Swaps became effective June 28, 2013, and amortize in proportion to the term loan. On October 21, 2014, Walnut Creek amended the credit agreement to increase its term loan borrowings by an additional $10 million , and to reduce the related interest rate to LIBOR plus 1.625% through September 30, 2018, LIBOR plus 1.75% from October 1, 2018, through September 30, 2022, and LIBOR plus 1.875% from October 1, 2022, through the maturity date. The fee on the working capital facility was reduced to 0.5% . The proceeds were utilized to make a distribution of $6 million to WCEP Holdings LLC with the remaining $4 million utilized to fund the costs of the amendment. In addition, Walnut Creek entered into an additional interest rate swap to maintain the minimum of 90% of the outstanding notional amount being swapped to a fixed interest rate. Walnut Creek pays its counterparty the equivalent of a 4.0025% fixed interest payment on a predetermined notional value, and quarterly, Walnut Creek receives the equivalent of a floating interest payment based on a three-month LIBOR calculated on the same notional value through July 31, 2020. All interest rate swap payments by Walnut Creek and its counterparties are made quarterly and the LIBOR is determined in advance of each interest period. Swaps became effective June 28, 2013, and amortize in proportion to the term loan. As of September 30, 2015 , $363 million was outstanding under the term loan, nothing was outstanding under the working capital facility, and $49 million of letters of credit were issued. WCEP Holdings LLC On July 27, 2011, WCEP Holdings LLC entered into a credit agreement with a group of lenders for a $53 million construction loan that was convertible to a term loan upon completion of the Walnut Creek project. The Walnut Creek project met the conditions for the WCEP Holdings LLC loan to convert to a term loan on June 21, 2013. The term loan has an interest rate of LIBOR plus an applicable margin of 4% . The term loan matures in May 2023. The term loan amortizes based upon a predetermined schedule. Under the terms of the credit agreement, WCEP Holdings LLC entered into two fixed for floating interest rate swaps that would fix the interest rate for a minimum of 90% of the outstanding notional amount. WCEP Holdings LLC will pay its counterparty the equivalent of a 4% fixed interest payment on a predetermined notional value, and quarterly, WCEP Holdings LLC will receive the equivalent of a floating interest payment based on a three-month LIBOR calculated on the same notional value through May 31, 2023. All interest rate swap payments by WCEP Holdings LLC and its counterparties are made quarterly and the LIBOR is determined in advance of each interest period. Swaps became effective June 28, 2013, and amortize in proportion to the term loan. On October 21, 2014, WCEP Holdings LLC amended the credit agreement to reduce the related interest rate to LIBOR plus 3% . The proceeds of the distribution from Walnut Creek were utilized to make an optional repayment of $6 million on the term loan. In addition, WCEP Holdings LLC partially terminated the interest rate agreements so that at least 90% and no more than 100% of the aggregate principal amount of the loans then outstanding will be subject to interest rate agreements. As of September 30, 2015 , $46 million was outstanding under the term loan. Avenal Solar Holdings LLC On March 18, 2015, Avenal Solar Holdings LLC, one of the Company's equity method investments, amended its credit agreement to increase its borrowings by $43 million and to reduce the related interest rate from 6 month LIBOR plus an applicable margin of 2.25% to 6 month LIBOR plus 1.75% from March 18, 2015, through March 17, 2022, 6 month LIBOR plus 2.00% from March 18, 2022, through March 17, 2027, and 6 month LIBOR plus 2.25% from March 18, 2027, through the maturity date. As a result of the credit agreement amendment, the Company received net proceeds of $20 million after fees from its 49.95% ownership in Avenal. Effective September 30, 2015, the Company increased its ownership to 50% by acquiring an additional 0.05% membership interest in Avenal. NRG West Holdings LLC On May 29, 2015, NRG West Holdings LLC amended its financing agreement to increase borrowings under the Tranche A facility by $5 million and to reduce the related interest rate to LIBOR plus an applicable margin of 1.625% from May 29, 2015, to August 31, 2017, LIBOR plus an applicable margin of 1.75% from September 1, 2017, to August 31, 2020, and LIBOR plus 1.875% from September 1, 2020, through the maturity date; to reduce the Tranche B loan interest rate to LIBOR plus an applicable margin of 2.250% from May 29, 2015, to August 31, 2017, LIBOR plus 2.375% from September 1, 2017, to August 31, 2020, and LIBOR plus an applicable margin of 2.50% from September 1, 2020, through the maturity date and to reduce the working capital facility by $9 million . The proceeds of the increased borrowing were used to pay costs associated with the refinancing. Further, the amendment resulted in a $7 million loss on debt extinguishment.

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting The Company’s segment structure reflects how management currently operates and allocates resources. The Company's businesses are primarily segregated based on conventional power generation, renewable businesses which consist of solar and wind, and the thermal and chilled water business. The Corporate segment reflects the Company's corporate costs. The Company's chief operating decision maker, its Chief Executive Officer, evaluates the performance of its segments based on operational measures including adjusted earnings before interest, depreciation and amortization, or Adjusted EBITDA, and cash available for distribution, or CAFD, as well as net income (loss). Three months ended September 30, 2015 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 86 $ 77 $ 46 $ — $ 209 Cost of operations 15 23 31 — 69 Depreciation and amortization 19 26 5 — 50 General and administrative — affiliate — — — 2 2 Acquisition-related transaction and integration costs — — — 1 1 Operating income (loss) 52 28 10 (3 ) 87 Equity in earnings of unconsolidated affiliates 3 16 — — 19 Other income, net — 1 — — 1 Loss on debt extinguishment — (2 ) — — (2 ) Interest expense (11 ) (32 ) (1 ) (15 ) (59 ) Net Income (Loss) $ 44 $ 11 $ 9 $ (18 ) $ 46 Total Assets $ 2,132 $ 4,214 $ 434 $ 64 $ 6,844 Three months ended September 30, 2014 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 80 $ 56 $ 48 $ — $ 184 Cost of operations 15 13 32 — 60 Depreciation and amortization 13 16 5 — 34 General and administrative — affiliate — — — 3 3 Acquisition-related transaction and integration costs — — — 2 2 Operating income (loss) 52 27 11 (5 ) 85 Equity in earnings of unconsolidated affiliates 4 7 — — 11 Other income, net — — — 1 1 Interest expense (14 ) (23 ) (2 ) (7 ) (46 ) Net Income (Loss) $ 42 $ 11 $ 9 $ (11 ) $ 51 Nine months ended September 30, 2015 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 247 $ 224 $ 135 $ — $ 606 Cost of operations 51 64 96 — 211 Depreciation and amortization 61 88 14 — 163 General and administrative — affiliate — — — 8 8 Acquisition-related transaction and integration costs — — — 2 2 Operating income (loss) 135 72 25 (10 ) 222 Equity in earnings of unconsolidated affiliates 10 19 — — 29 Other income, net 1 1 — — 2 Loss on debt extinguishment (7 ) (2 ) — — (9 ) Interest expense (36 ) (91 ) (5 ) (38 ) (170 ) Net Income (Loss) $ 103 $ (1 ) $ 20 $ (48 ) $ 74 Nine months ended September 30, 2014 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 223 $ 118 $ 156 $ — $ 497 Cost of operations 41 24 108 — 173 Depreciation and amortization 60 38 14 — 112 General and administrative — affiliate — — — 7 7 Acquisition-related transaction and integration costs — — — 2 2 Operating income (loss) 122 56 34 (9 ) 203 Equity in earnings of unconsolidated affiliates 11 15 — — 26 Other income, net — 1 — 1 2 Interest expense (40 ) (46 ) (6 ) (13 ) (105 ) Net Income (Loss) $ 93 $ 26 $ 28 $ (21 ) $ 126

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions Disclosure	Related Party Transactions Management Services Agreement by and between the Company and NRG NRG provides the Company with various operation, management, and administrative services, which include human resources, accounting, tax, legal, information systems, treasury, and risk management, as set forth in the Management Services Agreement. As of September 30, 2015 , the base management fee was approximately $7 million per year, subject to an inflation-based adjustment annually at an inflation factor based on the year-over-year U.S. consumer price index. The fee is also subject to adjustments following the consummation of future acquisitions and as a result of a change in the scope of services provided under the Management Services Agreement. During the nine months ended September 30, 2015 , the fee was increased by approximately $1 million per year primarily due to the acquisition of the January 2015 Drop Down Assets. Costs incurred under this agreement were $8 million and $7 million for the nine months ended September 30, 2015 , and 2014 , respectively, which included certain direct expenses incurred by NRG on behalf of the Company in addition to the base management fee. There was a balance of $5 million due to NRG in accounts payable — affiliate as of September 30, 2015 . Operation and Maintenance Services (O&M) Agreements by and between Thermal Entities and NRG On October 1, 2014, NRG entered into Plant O&M Services Agreements with certain wholly-owned subsidiaries of the Company. NRG provides necessary and appropriate services to operate and maintain the subsidiaries' plant operations, businesses and thermal facilities. NRG is to be reimbursed for the provided services, as well as for all reasonable and related expenses and expenditures, and payments to third parties for services and materials rendered to or on behalf of the parties to the agreements. NRG is not entitled to any management fee or mark-up under the agreements. Prior to October 1, 2014, NRG provided the same services to the Thermal Business on an informal basis. Total fees incurred under the agreements were $21 million for the nine months ended September 30, 2015 , and 2014 . There was a balance of $30 million and $22 million due to NRG in accounts payable — affiliate as of September 30, 2015 , and December 31, 2014 , respectively. Subsequent to quarter end, $7 million of the outstanding balance has been paid. Administrative Services Agreement by and between Marsh Landing and GenOn Energy Services, LLC Marsh Landing is a party to an administrative services agreement with GenOn Energy Services, LLC, a wholly-owned subsidiary of NRG, which provides invoice processing and payment on behalf of Marsh Landing. Marsh Landing reimburses GenOn Energy Services, LLC for the amounts paid by it. The Company reimbursed costs under this agreement of approximately $11 million for the nine months ended September 30, 2015 , and 2014 . There was a balance of $1 million and $4 million due to GenOn Energy Services, LLC in accounts payable — affiliate as of September 30, 2015 , and December 31, 2014 , respectively. O&M Services Agreements by and between El Segundo and NRG El Segundo Operations El Segundo incurs fees under an O&M agreement with NRG El Segundo Operations, Inc., a wholly-owned subsidiary of NRG. Under the O&M agreement, NRG El Segundo Operations, Inc. manages, operates and maintains the El Segundo facility for an initial term of ten years following the commercial operations date. For the nine months ended September 30, 2015 , and 2014 , the costs incurred under the agreement were approximately $4 million and $3 million , respectively. There was a balance of $1 million due to NRG El Segundo in accounts payable — affiliate as of September 30, 2015 , and December 31, 2014 . O&M Services Agreements by and between GenConn and NRG GenConn incurs fees under two O&M agreements with wholly-owned subsidiaries of NRG. The fees incurred under the agreements were $3 million and $5 million for the nine months ended September 30, 2015 , and 2014 , respectively. Administrative Services Agreement by and between CVSR and NRG CVSR is a party to an administrative services agreement with NRG Energy Services LLC, a wholly-owned subsidiary of NRG, which provides O&M services on behalf of CVSR. CVSR reimburses NRG Energy Services LLC for the amounts paid by it. CVSR reimbursed costs under this agreement of $4 million and $5 million for the nine months ended September 30, 2015 , and 2014 , respectively.

Condensed Consolidating Financi

Condensed Consolidating Financial Information Condensed Consolidating Financial Information	9 Months Ended
	Sep. 30, 2015
Condensed Consolidating Financial Information Disclosure [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of September 30, 2015 , Yield Operating LLC had outstanding $500 million of Senior Notes as shown in Note 8 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including those that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of September 30, 2015 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Three Months Ended September 30, 2015 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 7 $ 201 $ 1 $ — $ 209 Operating Costs and Expenses Cost of operations — 4 65 — — 69 Depreciation and amortization — 1 49 — — 50 General and administrative — affiliate — — — 2 — 2 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses — 5 114 3 — 122 Operating Income (Loss) — 2 87 (2 ) — 87 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 51 (9 ) — 41 (83 ) — Equity in earnings of unconsolidated affiliates — — — 19 — 19 Other income, net — — 1 — — 1 Loss on debt extinguishment — — (2 ) — — (2 ) Interest expense — — (45 ) (14 ) — (59 ) Total other income (expense), net 51 (9 ) (46 ) 46 (83 ) (41 ) Net Income (Loss) 51 (7 ) 41 44 (83 ) 46 Less: Net income (loss) attributable to noncontrolling interests — — 2 (7 ) — (5 ) Net Income (Loss) Attributable to $ 51 $ (7 ) $ 39 $ 51 $ (83 ) $ 51 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Nine Months Ended September 30, 2015 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 17 $ 580 $ 9 $ — $ 606 Operating Costs and Expenses Cost of operations — 11 200 — — 211 Depreciation and amortization — 3 160 — — 163 General and administrative — affiliate — — — 8 — 8 Acquisition-related transaction and integration costs — — — 2 — 2 Total operating costs and expenses — 14 360 10 — 384 Operating Income (Loss) — 3 220 (1 ) — 222 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 72 (28 ) — 86 (130 ) — Equity in earnings of unconsolidated affiliates — — — 29 — 29 Other income, net — — 2 — — 2 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (132 ) (38 ) — (170 ) Total other income (expense), net 72 (28 ) (139 ) 77 (130 ) (148 ) Net Income (Loss) 72 (25 ) 81 76 (130 ) 74 Less: Net (loss) income attributable to noncontrolling interests — — (2 ) 4 — 2 Net Income (Loss) Attributable to $ 72 $ (25 ) $ 83 $ 72 $ (130 ) $ 72 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) For the Three Months Ended September 30, 2015 NRG Yield LLC Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Net Income (Loss) $ 51 $ (7 ) $ 41 $ 44 $ (83 ) $ 46 Other Comprehensive Loss Unrealized loss on derivatives (38 ) — (35 ) (38 ) 73 (38 ) Other comprehensive loss (38 ) — (35 ) (38 ) 73 (38 ) Comprehensive Income (Loss) 13 (7 ) 6 6 (10 ) 8 Less: Comprehensive (loss) income attributable to noncontrolling interests — — 2 (7 ) — (5 ) Comprehensive Income Attributable to NRG Yield LLC $ 13 $ (7 ) $ 4 $ 13 $ (10 ) $ 13 (a) All significant intercompany transactions have been eliminated in consolidation. For the Nine Months Ended September 30, 2015 NRG Yield LLC Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Net Income (Loss) $ 72 $ (25 ) $ 81 $ 76 $ (130 ) $ 74 Other Comprehensive Loss Unrealized loss on derivatives (38 ) — (35 ) (38 ) 73 (38 ) Other comprehensive loss (38 ) — (35 ) (38 ) 73 (38 ) Comprehensive Income (Loss) 34 (25 ) 46 38 (57 ) 36 Less: Comprehensive (loss) income attributable to noncontrolling interests — — (2 ) 4 — 2 Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 34 $ (25 ) $ 48 $ 34 $ (57 ) $ 34 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS September 30, 2015 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 50 $ — $ 75 $ — $ — $ 125 Restricted cash — — 69 — — 69 Accounts receivable — trade — 3 101 — — 104 Accounts receivable — affiliate 20 23 8 13 (61 ) 3 Inventory — 2 28 — — 30 Derivative instruments — — — 3 — 3 Notes receivable — — 7 5 (5 ) 7 Prepayments and other current assets — — 24 1 — 25 Total current assets 70 28 312 22 (66 ) 366 Net property, plant and equipment — 61 4,373 — — 4,434 Other Assets Investment in consolidated subsidiaries 1,915 564 — 2,646 (5,125 ) — Equity investments in affiliates — 28 — 525 — 553 Notes receivable — — 11 — — 11 Intangible assets, net — 57 1,320 — — 1,377 Derivative instruments — — — — — — Other non-current assets — — 94 9 — 103 Total other assets 1,915 649 1,425 3,180 (5,125 ) 2,044 Total Assets $ 1,985 $ 738 $ 6,110 $ 3,202 $ (5,191 ) $ 6,844 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) September 30, 2015 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (a) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 229 $ — $ (5 ) $ 224 Accounts payable — 1 20 1 — 22 Accounts payable — affiliate — 6 45 67 (61 ) 57 Derivative instruments — — 41 1 — 42 Accrued expenses and other current liabilities — 1 70 8 — 79 Total current liabilities — 8 405 77 (66 ) 424 Other Liabilities Long-term debt — external — — 3,098 592 — 3,690 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 74 — — 74 Other non-current liabilities — — 53 — — 53 Total non-current liabilities — — 3,225 1,210 — 4,435 Total Liabilities — 8 3,630 1,287 (66 ) 4,859 Commitments and Contingencies Members' Equity Contributed capital 1,728 790 2,402 1,693 (4,885 ) 1,728 Retained earnings (accumulated deficit) 158 (57 ) 83 123 (149 ) 158 Noncontrolling interest 195 — 71 195 (266 ) 195 Accumulated other comprehensive loss (96 ) (3 ) (76 ) (96 ) 175 (96 ) Total Members' Equity 1,985 730 2,480 1,915 (5,125 ) 1,985 Total Liabilities and Members’ Equity $ 1,985 $ 738 $ 6,110 $ 3,202 $ (5,191 ) $ 6,844 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Nine Months Ended September 30, 2015 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by Operating Activities $ — $ 28 $ 183 $ 58 $ 269 Cash Flows from Investing Activities Intercompany transactions between Yield LLC and subsidiaries (501 ) — — 501 — Acquisition of business, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (489 ) (489 ) Capital expenditures — — (16 ) — (16 ) Increase in restricted cash — — (24 ) — (24 ) Decrease in notes receivable — — 5 — 5 Net investments in unconsolidated affiliates — (19 ) — (316 ) (335 ) Net Cash Used in Investing Activities (501 ) (19 ) (35 ) (341 ) (896 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (277 ) (9 ) — 286 — Contributions from noncontrolling interests — — — 119 119 Proceeds from the issuance of Class C units 599 — — — 599 Payment of distributions (99 ) — — — (99 ) Proceeds from issuance of long-term debt — external — — 5 297 302 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payment of debt issuance costs — — (6 ) (1 ) (7 ) Payments for long-term debt — external — — (150 ) (699 ) (849 ) Net Cash Provided by (Used in) Financing Activities 223 (9 ) (151 ) 283 346 Net Decrease in Cash and Cash Equivalents (278 ) — (3 ) — (281 ) Cash and Cash Equivalents at Beginning of Period 328 — 78 — 406 Cash and Cash Equivalents at End of Period $ 50 $ — $ 75 $ — $ 125 NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Three Months Ended September 30, 2014 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 7 $ 177 $ — $ — $ 184 Operating Costs and Expenses Cost of operations — 4 56 — — 60 Depreciation and amortization — 1 33 — — 34 General and administrative — affiliate — — — 3 — 3 Acquisition-related transaction and integration costs — — — 2 — 2 Total operating costs and expenses — 5 89 5 — 99 Operating Income (Loss) — 2 88 (5 ) — 85 Other Income (Expense) Equity in earnings of consolidated affiliates 50 (8 ) — 52 (94 ) — Equity in earnings of unconsolidated affiliates — — — 11 — 11 Other income, net 1 — — — — 1 Interest expense — — (38 ) (8 ) — (46 ) Total other income (expense), net 51 (8 ) (38 ) 55 (94 ) (34 ) Net Income $ 51 $ (6 ) $ 50 $ 50 $ (94 ) $ 51 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Nine Months Ended September 30, 2014 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 19 $ 478 $ — $ — $ 497 Operating Costs and Expenses Cost of operations — 12 161 — — 173 Depreciation and amortization — 3 109 — — 112 General and administrative — affiliate — — — 7 — 7 Acquisition-related transaction and integration costs — — — 2 — 2 Total operating costs and expenses — 15 270 9 — 294 Operating Income (Loss) — 4 208 (9 ) — 203 Other Income (Expense) Equity in earnings of consolidated affiliates 125 (6 ) — 122 (241 ) — Equity in earnings of unconsolidated affiliates — — — 26 — 26 Other income, net 1 — 1 — — 2 Interest expense — — (91 ) (14 ) — (105 ) Total other income (expense), net 126 (6 ) (90 ) 134 (241 ) (77 ) Net Income $ 126 $ (2 ) $ 118 $ 125 $ (241 ) $ 126 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2014 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (a) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 328 $ — $ 78 $ — $ — $ 406 Restricted cash — — 45 — — 45 Accounts receivable — trade — 3 82 — — 85 Accounts receivable — affiliate (256 ) 17 66 268 (95 ) — Inventory — 1 26 — — 27 Notes receivable — — 6 — — 6 Prepayments and other current assets — 1 20 — — 21 Total current assets 72 22 323 268 (95 ) 590 Net property, plant and equipment — 56 4,410 — — 4,466 Other Assets Investment in consolidated subsidiaries 1,664 585 — 2,045 (4,294 ) — Equity investments in affiliates — — — 227 — 227 Notes receivable — — 15 — — 15 Intangible assets, net — 58 1,365 — — 1,423 Derivative instruments — — 2 — — 2 Other non-current assets — — 93 10 — 103 Total other assets 1,664 643 1,475 2,282 (4,294 ) 1,770 Total Assets $ 1,736 $ 721 $ 6,208 $ 2,550 $ (4,389 ) $ 6,826 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2014 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (a) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 214 $ — $ — $ 214 Accounts payable — 1 19 — — 20 Accounts payable — affiliate — 8 99 33 (95 ) 45 Derivative instruments — — 48 — — 48 Accrued expenses and other current liabilities — 2 43 16 — 61 Total current liabilities — 11 423 49 (95 ) 388 Other Liabilities Long-term debt — external — — 3,747 500 — 4,247 Long-term debt — affiliate — — — 337 — 337 Derivative instruments — — 69 — — 69 Other non-current liabilities — — 49 — — 49 Total non-current liabilities — — 3,865 837 — 4,702 Total Liabilities — 11 4,288 886 (95 ) 5,090 Commitments and Contingencies Members' Equity Contributed capital 1,609 747 1,848 1,542 (4,137 ) 1,609 Retained earnings (Accumulated deficit) 185 (34 ) 113 180 (259 ) 185 Accumulated other comprehensive loss (58 ) (3 ) (41 ) (58 ) 102 (58 ) Total Members' Equity 1,736 710 1,920 1,664 (4,294 ) 1,736 Total Liabilities and Members’ Equity $ 1,736 $ 721 $ 6,208 $ 2,550 $ (4,389 ) $ 6,826 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Nine Months Ended September 30, 2014 NRG Yield LLC Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by Operating Activities $ 30 $ 105 $ 114 $ 249 Cash Flows from Investing Activities Acquisition of businesses, net of cash acquired — — (901 ) (901 ) Acquisition of Drop Down Assets, net of cash acquired — — (336 ) (336 ) Capital expenditures — (28 ) — (28 ) Decrease in restricted cash — 20 — 20 Decrease in notes receivable — 4 2 6 Proceeds from renewable energy grants — 137 — 137 Investments in unconsolidated affiliates — — (17 ) (17 ) Other — 11 — 11 Net Cash Provided by (Used in) Investing Activities — 144 (1,252 ) (1,108 ) Cash Flows from Financing Activities Capital contributions from NRG — 2 — 2 Distributions and return of capital to NRG — (45 ) — (45 ) Proceeds from the issuance of Class A units 630 — — 630 Payment of distributions (72 ) — — (72 ) Proceeds from issuance of long-term debt - external — 79 500 579 Transfer of funds under intercompany cash management arrangement (290 ) — 290 — Payments of long-term debt- external — (220 ) — (220 ) Proceeds from long-term debt - affiliate — — 337 337 Payment of debt issuance costs — (9 ) (9 ) (18 ) Net Cash Provided by (Used in) Financing Activities 268 (193 ) 1,118 1,193 Net Increase (Decrease) in Cash and Cash Equivalents 298 56 (20 ) 334 Cash and Cash Equivalents at Beginning of Period 3 36 20 59 Cash and Cash Equivalents at End of Period $ 301 $ 92 $ — $ 393

Summary of Significant Accoun18

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Distributions [Policy Text Block]	Distributions Third Quarter 2015 Second Quarter 2015 First Quarter 2015 Distributions per unit A, B $ 0.21 $ 0.20 $ 0.39 Distributions per unit C, D $ 0.21 $ 0.20 N/A On November 4, 2015 , the Company announced the declaration of a distribution on its Class A, Class B, Class C and Class D units of $0.215 per unit payable on December 15, 2015 to unit holders of record as of December 1, 2015 .
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions. These estimates and assumptions impact the reported amount of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the consolidated financial statements. They also impact the reported amount of net earnings during the reporting period. Actual results could be different from these estimates.
Recent Accounting Developments	Recent Accounting Developments ASU 2015-16 — In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments , or ASU No. 2015-16. The amendments of ASU No. 2015-16 require that an acquirer recognize measurement period adjustments to the provisional amounts recognized in a business combination in the reporting period during which the adjustments are determined. Additionally, the amendments of ASU No. 2015-16 require the acquirer to record in the same period's financial statements the effect on earnings of changes in depreciation, amortization or other income effects, if any, as a result of the measurement period adjustment, calculated as if the accounting had been completed at the acquisition date as well as disclosing on either the face of the income statement or in the notes the portion of the amount recorded in current period earnings that would have been recorded in previous reporting periods. The guidance in ASU No. 2015-16 is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The amendments should be applied prospectively. The adoption of this standard is not expected to have a material impact on the Company's results of operations, cash flows or financial position. ASU 2015-03 and ASU 2015-15 — In April 2015, the FASB issued ASU No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs , or ASU No. 2015-03. The amendments of ASU No. 2015-03 were issued to reduce complexity in the balance sheet presentation of debt issuance costs. ASU No. 2015-03 requires that debt issuance costs be presented in the balance sheet as a direct deduction from the carrying amount of debt liability, consistent with debt discounts or premiums. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this standard. Additionally, in August 2015, the FASB issued ASU No. 2015-15, Interest - Imputation of Interest (Subtopic 835-30): Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements, or ASU No. 2015-15, as ASU No. 2015-03 did not specifically address presentation or subsequent measurement of debt issuance costs related to line-of-credit arrangements. ASU No. 2015-15 allows an entity to continue to defer and present debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. The guidance in ASU No. 2015-03 and ASU No. 2015-15 is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted for financial statements that have not been previously issued. Had the Company adopted this guidance early, other assets would have been lower by $ 54 million and $ 61 million with corresponding decreases in debt as of September 30, 2015 , and December 31, 2014 , respectively. The adoption of this standard will have no impact on the Company's results of operations, cash flows or net assets. ASU 2015-02 — In February 2015, the FASB issued ASU No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis , or ASU No. 2015-02. The amendments of ASU No. 2015-02 were issued in an effort to minimize situations under previously existing guidance in which a reporting entity was required to consolidate another legal entity in which that reporting entity did not have: (1) the ability through contractual rights to act primarily on its own behalf; (2) ownership of the majority of the legal entity's voting rights; or (3) the exposure to a majority of the legal entity's economic benefits. ASU No. 2015-02 affects reporting entities that are required to evaluate whether they should consolidate certain legal entities. All legal entities are subject to reevaluation under the revised consolidation model. The guidance in ASU No. 2015-02 is effective for periods beginning after December 15, 2015. Early adoption is permitted. The Company adopted the standard effective January 1, 2015 and the adoption of this standard did not impact the Company's results of operations, cash flows or financial position. ASU 2014-16 — In November 2014, the FASB issued ASU No. 2014-16, Derivatives and Hedging (Topic 815): Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity , or ASU No. 2014-16. The amendments of ASU No. 2014-16 clarify how U.S. GAAP should be applied in determining whether the nature of a host contract is more akin to debt or equity and in evaluating whether the economic characteristics and risks of an embedded feature are "clearly and closely related" to its host contract. The guidance in ASU No. 2014-16 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted. The Company adopted the standard effective January 1, 2015 and the adoption of this standard did not impact the Company's results of operations, cash flows or financial position. ASU 2014-09 — In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), or ASU No. 2014-09. The amendments of ASU No. 2014-09 complete the joint effort between the FASB and the International Accounting Standards Board, or IASB, to develop a common revenue standard for U.S. GAAP and International Financial Reporting Standards, or IFRS, and to improve financial reporting. The guidance in ASU No. 2014-09 provides that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for the goods or services provided and establishes the following steps to be applied by an entity: (1) identify the contract with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies the performance obligation. In August 2015, the FASB issued ASU 2015-14, which formally deferred the effective date by one year to make the guidance of ASU No. 2014-09 effective for annual reporting periods beginning after December 15, 2017, including interim periods therein. Early adoption is permitted, but not prior to the original effective date, which was for annual reporting periods beginning after December 15, 2016. The Company is currently evaluating the impact of the standard on the Company's results of operations, cash flows and financial position.
Noncontrolling Interest Disclosure [Text Block]	The following table reflects the changes in the Company's noncontrolling interest balance: (In millions) Balance as of December 31, 2014 — Contributions from noncontrolling interest for Alta Wind X-X1 TE Holdco 119 Noncontrolling interest acquired in Spring Canyon acquisition 74 Comprehensive income 2 Balance as of September 30, 2015 $ 195 On June 30, 2015, Yield Operating LLC sold an economic interest in Alta Wind X-XI TE Holdco, holder of the Alta Wind X and Alta Wind XI projects, to a financial institution in order to monetize cash and tax attributes, primarily production tax credits. The net proceeds of $119 million are reflected as noncontrolling interest in the Company's balance sheet. As described in Note 3, Business Acquisitions , the Company acquired Spring Canyon on May 7, 2015. The Company owns 90.1% of the Class B shares of Spring Canyon. The seller, Invenergy, owns the remaining 9.9% of the Class B shares and the Class A shares are owned by a tax equity investor. The interests of Invenergy and the tax equity investor of $74 million are shown as noncontrolling interests.

Segment Reporting Segment Repor

Segment Reporting Segment Reporting (Policies)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segment Reporting, Policy [Policy Text Block]	The Company’s segment structure reflects how management currently operates and allocates resources. The Company's businesses are primarily segregated based on conventional power generation, renewable businesses which consist of solar and wind, and the thermal and chilled water business. The Corporate segment reflects the Company's corporate costs. The Company's chief operating decision maker, its Chief Executive Officer, evaluates the performance of its segments based on operational measures including adjusted earnings before interest, depreciation and amortization, or Adjusted EBITDA, and cash available for distribution, or CAFD, as well as net income (loss).

Nature of Business Nature of Bu

Nature of Business Nature of Business (Tables)	9 Months Ended
	Sep. 30, 2015
Nature of Business Disclosure [Abstract]
IPO of NRG Yield [Table Text Block]	The following table represents the structure of the Company as of September 30, 2015 :
Schedule of Ownership [Table Text Block]	As of September 30, 2015 , the Company's operating assets are comprised of the following projects: Projects Percentage Ownership Net Capacity (MW) (a) Offtake Counterparty Expiration Conventional GenConn Middletown (b) 50 % 95 Connecticut Light & Power 2041 GenConn Devon (b) 50 % 95 Connecticut Light & Power 2040 Marsh Landing 100 % 720 Pacific Gas and Electric 2023 El Segundo 100 % 550 Southern California Edison 2023 Walnut Creek 100 % 485 Southern California Edison 2023 1,945 Utility Scale Solar Alpine 100 % 66 Pacific Gas and Electric 2033 Avenal (b) 50 % 23 Pacific Gas and Electric 2031 Avra Valley 100 % 25 Tucson Electric Power 2032 Blythe 100 % 21 Southern California Edison 2029 Borrego 100 % 26 San Diego Gas and Electric 2038 Roadrunner 100 % 20 El Paso Electric 2031 CVSR 48.95 % 122 Pacific Gas and Electric 2038 Kansas South 100 % 20 Pacific Gas and Electric 2033 TA High Desert 100 % 20 Southern California Edison 2033 Desert Sunlight 250 25 % 63 Southern California Edison 2035 Desert Sunlight 300 25 % 75 Pacific Gas and Electric 2040 481 Distributed Solar AZ DG Solar Projects 100 % 5 Various 2025 - 2033 PFMG DG Solar Projects 51 % 4 Various 2032 9 Wind Alta I 100 % 150 Southern California Edison 2035 Alta II 100 % 150 Southern California Edison 2035 Alta III 100 % 150 Southern California Edison 2035 Alta IV 100 % 102 Southern California Edison 2035 Alta V 100 % 168 Southern California Edison 2035 Alta X (c)(d) 100 % 137 Southern California Edison 2038 (c) Alta XI (c)(d) 100 % 90 Southern California Edison 2038 (c) South Trent 100 % 101 AEP Energy Partners 2029 Laredo Ridge 100 % 80 Nebraska Public Power District 2031 Taloga 100 % 130 Oklahoma Gas & Electric 2031 Pinnacle 100 % 55 Maryland Department of General Services and University System of Maryland 2031 Buffalo Bear 100 % 19 Western Farmers Electric Co-operative 2033 Spring Canyon II (c) 90.1 % 31 Platte River Power Authority 2038 Spring Canyon III (c) 90.1 % 26 Platte River Power Authority 2039 1,389 Thermal Thermal equivalent MWt (e) 100 % 1,310 Various Various Thermal generation 100 % 124 Various Various Total net capacity (excluding equivalent MWt) (f) 3,948 (a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015 . (b) On September 30, 2015, the Company acquired NRG's remaining 0.05% for an immaterial amount. (c) Projects are part of tax equity arrangements, as further described in Note 2, Summary of Significant Accounting Policies . (d) PPA begins on January 1, 2016. (e) For thermal energy, net capacity represents MWt for steam or chilled water and excludes 134 MWt available under the right-to-use provisions contained in agreements between two of the Company's thermal facilities and certain of its customers. (f) Total net capacity excludes capacity for RPV Holdco and DGPV Holdco, which are consolidated by NRG, as further described in Note 5, Variable Interest Entities .

Summary of Significant Accoun21

Summary of Significant Accounting Policies Noncontrolling Interest Disclosure (Tables)	9 Months Ended
	Sep. 30, 2015
Noncontrolling Interest [Abstract]
Schedule of Change in Noncontrolling Interest [Table Text Block]	The following table reflects the changes in the Company's noncontrolling interest balance: (In millions) Balance as of December 31, 2014 — Contributions from noncontrolling interest for Alta Wind X-X1 TE Holdco 119 Noncontrolling interest acquired in Spring Canyon acquisition 74 Comprehensive income 2 Balance as of September 30, 2015 $ 195

Business Acquisitions Business

Business Acquisitions Business Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2015
November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The following is a summary of assets and liabilities transferred in connection with the acquisition as of September 30, 2015 : NRG Wind TE Holdco (In millions) Current assets $ 34 Property, plant and equipment 673 Non-current assets 179 Total assets 886 Debt 193 Other current and non-current liabilities 33 Total liabilities 226 Less: noncontrolling interest $ 289 Net assets acquired $ 371
January 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]
Business Acquisition, Pro Forma Information [Table Text Block]	The following unaudited supplemental pro forma information represents the results of operations as if the Company had acquired the January 2015 Drop Down Assets on January 1, 2014, including the impact of acquisition accounting with respect to NRG's acquisition of the projects. For the nine months ended (In millions) September 30, 2014 Operating revenues $ 523 Net income 122
Alta Wind Portfolio [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price [Table Text Block]	The purchase price of $923 million was allocated as follows: Acquisition Date Fair Value at December 31, 2014 Measurement period adjustments Revised Acquisition Date (In millions) Assets Cash $ 22 $ — $ 22 Current and non-current assets 49 (2 ) 47 Property, plant and equipment 1,304 6 1,310 Intangible assets 1,177 (6 ) 1,171 Total assets acquired 2,552 (2 ) 2,550 Liabilities Debt 1,591 — 1,591 Current and non-current liabilities 38 (2 ) 36 Total liabilities assumed 1,629 (2 ) 1,627 Net assets acquired $ 923 $ — $ 923
Alta X and XI TE Holdco [Member]
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Information [Table Text Block]	For the three months ended For the nine months ended (In millions) September 30, 2015 September 30, 2014 September 30, 2015 September 30, 2014 Operating revenues $ 225 $ 200 $ 660 $ 561 Net income 35 48 57 96

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	The Company’s major classes of property, plant, and equipment were as follows: September 30, 2015 December 31, 2014 Depreciable Lives (In millions) Facilities and equipment $ 4,837 $ 4,709 2 - 40 Years Land and improvements 92 87 Construction in progress 4 8 Total property, plant and equipment 4,933 4,804 Accumulated depreciation (499 ) (338 ) Net property, plant and equipment $ 4,434 $ 4,466

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2015
NRG RPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Summarized financial information of equity method investment	The following illustrates the structure of RPV Holdco:
NRG DGPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Summarized financial information of equity method investment	The following illustrates the structure of DGPV Holdco:
GCE Holding LLC [Member]
Schedule of Equity Method Investments [Line Items]
Summarized financial information of equity method investment	The following table presents summarized financial information for GCE Holding LLC: Three months ended September 30, Nine months ended September 30, (In millions) 2015 2014 2015 2014 Income Statement Data: Operating revenues $ 21 $ 18 $ 61 $ 62 Operating income 9 10 29 30 Net income $ 6 $ 7 $ 20 $ 21 September 30, 2015 December 31, 2014 Balance Sheet Data: (In millions) Current assets $ 32 $ 33 Non-current assets 420 438 Current liabilities 16 20 Non-current liabilities $ 216 $ 223
Desert Sunlight [Member]
Schedule of Equity Method Investments [Line Items]
Summarized financial information of equity method investment	The following tables present summarized financial information for Desert Sunlight Investment Holdings, LLC: Three months ended September 30, Nine months ended September 30, (In millions) 2015 2014 2015 2014 Income Statement Data: Operating revenues $ 73 $ 48 $ 170 $ 102 Operating income 51 33 108 58 Net income $ 39 $ 22 $ 70 $ 27 September 30, 2015 December 31, 2014 Balance Sheet Data: (In millions) Current assets $ 381 $ 706 Non-current assets 1,508 1,519 Current liabilities 91 436 Non-current liabilities $ 1,141 $ 1,152
Alta X and XI TE Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Schedule of Variable Interest Entities [Table Text Block]	The summarized financial information for Alta TE Holdco consisted of the following: (In millions) September 30, 2015 Other current and non-current assets $ 20 Property, plant and equipment 490 Intangible assets 287 Total assets 797 Current and non-current liabilities 13 Total liabilities 13 Noncontrolling interest 124 Net assets less noncontrolling interests $ 660

Fair Value of Financial Instr25

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Estimated carrying values and fair values of the Company's recorded financial instruments	The estimated carrying amounts and fair values of the Company’s recorded financial instruments not carried at fair market value are as follows: As of September 30, 2015 As of December 31, 2014 Carrying Amount Fair Value Carrying Amount Fair Value (In millions) Assets: Notes receivable, including current portion $ 18 $ 18 $ 21 $ 21 Liabilities: Long-term debt — affiliate 618 542 337 386 Long-term debt — external, including current portion $ 3,914 $ 3,852 $ 4,461 $ 4,478
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The Company records its derivative assets and liabilities at fair market value on its consolidated balance sheet. The following table presents assets and liabilities measured and recorded at fair value on the Company's consolidated balance sheets on a recurring basis and their level within the fair value hierarchy: As of September 30, 2015 As of December 31, 2014 Fair Value (a) Fair Value (a) Fair Value (b) (In millions) Level 1 Level 2 Level 2 Derivative assets: Commodity contracts $ — $ 3 $ — Interest rate contracts — — 2 Total assets — 3 2 Derivative liabilities: Commodity contracts 1 2 3 Interest rate contracts — 113 114 Total liabilities $ 1 $ 115 $ 117

Accounting for Derivative Ins26

Accounting for Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2015
Accounting for Derivative Instruments and Hedging Activities Disclosure [Abstract]
Net notional volume buy/(sell) of NRG Yield's open derivative transactions broken out by commodity	The following table summarizes the net notional volume buy/(sell) of the Company's open derivative transactions broken out by commodity as of September 30, 2015 , and December 31, 2014 . Total Volume September 30, 2015 December 31, 2014 Commodity Units (In millions) Natural Gas MMBtu 4 2 Interest Dollars $ 1,786 $ 2,817
Fair value within the derivative instrument valuation on the balance sheets	The following table summarizes the fair value within the derivative instrument valuation on the balance sheet: Fair Value Derivative Assets Derivative Liabilities September 30, 2015 December 31, 2014 September 30, 2015 December 31, 2014 (In millions) Derivatives Designated as Cash Flow Hedges: Interest rate contracts current $ — $ — $ 36 $ 40 Interest rate contracts long-term — 2 67 49 Total Derivatives Designated as Cash Flow Hedges — 2 103 89 Derivatives Not Designated as Cash Flow Hedges : Interest rate contracts current — — 3 5 Interest rate contracts long-term — — 7 20 Commodity contracts current 3 — 3 3 Total Derivatives Not Designated as Cash Flow Hedges 3 — 13 28 Total Derivatives $ 3 $ 2 $ 116 $ 117
Offsetting of derivatives by counterparty master agreement level and collateral received or paid	The Company has elected to present derivative assets and liabilities on the balance sheet on a trade-by-trade basis and does not offset amounts at the counterparty master agreement level. As of September 30, 2015 , there was no outstanding collateral paid or received. The following table summarizes the offsetting of derivatives by counterparty master agreement level: Gross Amounts Not Offset in the Statement of Financial Position As of September 30, 2015 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts: (In millions) Derivative assets $ 3 $ (1 ) $ 2 Derivative liabilities (3 ) 1 (2 ) Total commodity contracts — — — Interest rate contracts: Derivative liabilities (113 ) — (113 ) Total interest rate contracts (113 ) — (113 ) Total derivative instruments $ (113 ) $ — $ (113 ) Gross Amounts Not Offset in the Statement of Financial Position As of December 31, 2014 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts: (In millions) Derivative liabilities $ (3 ) $ — $ (3 ) Total commodity contracts (3 ) — (3 ) Interest rate contracts: Derivative assets 2 (2 ) — Derivative liabilities (114 ) 2 (112 ) Total interest rate contracts (112 ) — (112 ) Total derivative instruments $ (115 ) $ — $ (115 )
Effects of NRG Yield's accumulated OCI balance attributable to interest rate swaps designated as cash flow hedge derivatives, net of tax	The following table summarizes the effects on the Company’s accumulated OCL balance attributable to interest rate swaps designated as cash flow hedge derivatives: Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 (In millions) Accumulated OCL beginning balance $ (58 ) $ (35 ) $ (58 ) $ (1 ) Reclassified from accumulated OCL to income due to realization of previously deferred amounts 4 3 11 10 Mark-to-market of cash flow hedge accounting contracts (42 ) 1 (49 ) (40 ) Accumulated OCL ending balance $ (96 ) $ (31 ) $ (96 ) $ (31 ) Losses expected to be realized from OCL during the next 12 months $ (18 ) $ (18 )

Long-term Debt (Tables)

Long-term Debt (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Schedule of long-term debt	This footnote should be read in conjunction with the complete description under Note 9, Long-term Debt , to the Company's audited consolidated financial statements for the year ended December 31, 2014, included in the Company's Prospectus dated June 22, 2015. Long-term debt consisted of the following: September 30, 2015 December 31, 2014 September 30, 2015, interest rate % (a) (In millions, except rates) Senior Notes, due 2024 $ 500 $ 500 5.375 Long-term debt - affiliate, due 2019 337 337 3.580 Long-term debt - affiliate, due 2020 281 — 3.325 NRG Yield LLC and NRG Yield Operating LLC Revolving Credit Facility, due 2019 (b) 92 — L+2.75 Project-level debt: Alta Wind I, lease financing arrangement, due 2034 255 261 7.015 Alta Wind II, lease financing arrangement, due 2034 200 205 5.696 Alta Wind III, lease financing arrangement, due 2034 208 212 6.067 Alta Wind IV, lease financing arrangement, due 2034 135 138 5.938 Alta Wind V, lease financing arrangement, due 2035 215 220 6.071 Alta Wind X, due 2021 — 300 L+2.00 Alta Wind XI, due 2021 — 191 L+2.00 Alta Realty Investments, due 2031 33 34 7.00 Alta Wind Asset Management, due 2031 19 20 L+2.375 NRG West Holdings LLC, due 2023 (El Segundo Energy Center) 485 506 L+1.625 - L+2.25 NRG Marsh Landing LLC, due 2017 and 2023 431 464 L+1.75 - L+1.875 Walnut Creek Energy, due 2023 363 391 L+1.625 Tapestry Wind LLC, due 2021 184 192 L+1.625 NRG Solar Alpine LLC, due 2014 and 2022 156 163 L+1.75 NRG Energy Center Minneapolis LLC, due 2017 and 2025 110 121 5.95 -7.25 Laredo Ridge LLC, due 2028 105 108 L+1.875 NRG Solar Borrego LLC, due 2025 and 2038 73 75 L+ 2.50/5.65 South Trent Wind LLC, due 2020 62 65 L+1.625 NRG Solar Avra Valley LLC, due 2031 61 63 L+1.75 TA High Desert LLC, due 2020 and 2032 54 55 L+2.50/5.15 WCEP Holdings LLC, due 2023 46 46 L+3.00 NRG Roadrunner LLC, due 2031 40 42 L+1.625 NRG Solar Kansas South LLC, due 2031 34 35 L+2.00 NRG Solar Blythe LLC, due 2028 22 22 L+1.625 PFMG and related subsidiaries financing agreement, due 2030 30 31 6.00 NRG Energy Center Princeton LLC, due 2017 1 1 5.95 Subtotal project-level debt: 3,322 3,961 Total debt 4,532 4,798 Less current maturities 224 214 Total long-term debt $ 4,308 $ 4,584 (a) As of September 30, 2015 , L+ equals 3 month LIBOR plus x%, except for the NRG Marsh Landing term loan, Walnut Creek term loan, and the Revolving Credit Facility where L+ equals 1 month LIBOR plus x% and Kansas South where L+ equals 6 month LIBOR plus x%.

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Three months ended September 30, 2015 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 86 $ 77 $ 46 $ — $ 209 Cost of operations 15 23 31 — 69 Depreciation and amortization 19 26 5 — 50 General and administrative — affiliate — — — 2 2 Acquisition-related transaction and integration costs — — — 1 1 Operating income (loss) 52 28 10 (3 ) 87 Equity in earnings of unconsolidated affiliates 3 16 — — 19 Other income, net — 1 — — 1 Loss on debt extinguishment — (2 ) — — (2 ) Interest expense (11 ) (32 ) (1 ) (15 ) (59 ) Net Income (Loss) $ 44 $ 11 $ 9 $ (18 ) $ 46 Total Assets $ 2,132 $ 4,214 $ 434 $ 64 $ 6,844 Three months ended September 30, 2014 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 80 $ 56 $ 48 $ — $ 184 Cost of operations 15 13 32 — 60 Depreciation and amortization 13 16 5 — 34 General and administrative — affiliate — — — 3 3 Acquisition-related transaction and integration costs — — — 2 2 Operating income (loss) 52 27 11 (5 ) 85 Equity in earnings of unconsolidated affiliates 4 7 — — 11 Other income, net — — — 1 1 Interest expense (14 ) (23 ) (2 ) (7 ) (46 ) Net Income (Loss) $ 42 $ 11 $ 9 $ (11 ) $ 51 Nine months ended September 30, 2015 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 247 $ 224 $ 135 $ — $ 606 Cost of operations 51 64 96 — 211 Depreciation and amortization 61 88 14 — 163 General and administrative — affiliate — — — 8 8 Acquisition-related transaction and integration costs — — — 2 2 Operating income (loss) 135 72 25 (10 ) 222 Equity in earnings of unconsolidated affiliates 10 19 — — 29 Other income, net 1 1 — — 2 Loss on debt extinguishment (7 ) (2 ) — — (9 ) Interest expense (36 ) (91 ) (5 ) (38 ) (170 ) Net Income (Loss) $ 103 $ (1 ) $ 20 $ (48 ) $ 74 Nine months ended September 30, 2014 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 223 $ 118 $ 156 $ — $ 497 Cost of operations 41 24 108 — 173 Depreciation and amortization 60 38 14 — 112 General and administrative — affiliate — — — 7 7 Acquisition-related transaction and integration costs — — — 2 2 Operating income (loss) 122 56 34 (9 ) 203 Equity in earnings of unconsolidated affiliates 11 15 — — 26 Other income, net — 1 — 1 2 Interest expense (40 ) (46 ) (6 ) (13 ) (105 ) Net Income (Loss) $ 93 $ 26 $ 28 $ (21 ) $ 126

Condensed Consolidating Finan29

Condensed Consolidating Financial Information Condensed Consolidating Financial Information (Tables)	9 Months Ended
	Sep. 30, 2015
Condensed Consolidating Financial Information Disclosure [Abstract]
Condensed Cash Flow Statement [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Nine Months Ended September 30, 2015 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by Operating Activities $ — $ 28 $ 183 $ 58 $ 269 Cash Flows from Investing Activities Intercompany transactions between Yield LLC and subsidiaries (501 ) — — 501 — Acquisition of business, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (489 ) (489 ) Capital expenditures — — (16 ) — (16 ) Increase in restricted cash — — (24 ) — (24 ) Decrease in notes receivable — — 5 — 5 Net investments in unconsolidated affiliates — (19 ) — (316 ) (335 ) Net Cash Used in Investing Activities (501 ) (19 ) (35 ) (341 ) (896 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (277 ) (9 ) — 286 — Contributions from noncontrolling interests — — — 119 119 Proceeds from the issuance of Class C units 599 — — — 599 Payment of distributions (99 ) — — — (99 ) Proceeds from issuance of long-term debt — external — — 5 297 302 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payment of debt issuance costs — — (6 ) (1 ) (7 ) Payments for long-term debt — external — — (150 ) (699 ) (849 ) Net Cash Provided by (Used in) Financing Activities 223 (9 ) (151 ) 283 346 Net Decrease in Cash and Cash Equivalents (278 ) — (3 ) — (281 ) Cash and Cash Equivalents at Beginning of Period 328 — 78 — 406 Cash and Cash Equivalents at End of Period $ 50 $ — $ 75 $ — $ 125 NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Nine Months Ended September 30, 2014 NRG Yield LLC Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by Operating Activities $ 30 $ 105 $ 114 $ 249 Cash Flows from Investing Activities Acquisition of businesses, net of cash acquired — — (901 ) (901 ) Acquisition of Drop Down Assets, net of cash acquired — — (336 ) (336 ) Capital expenditures — (28 ) — (28 ) Decrease in restricted cash — 20 — 20 Decrease in notes receivable — 4 2 6 Proceeds from renewable energy grants — 137 — 137 Investments in unconsolidated affiliates — — (17 ) (17 ) Other — 11 — 11 Net Cash Provided by (Used in) Investing Activities — 144 (1,252 ) (1,108 ) Cash Flows from Financing Activities Capital contributions from NRG — 2 — 2 Distributions and return of capital to NRG — (45 ) — (45 ) Proceeds from the issuance of Class A units 630 — — 630 Payment of distributions (72 ) — — (72 ) Proceeds from issuance of long-term debt - external — 79 500 579 Transfer of funds under intercompany cash management arrangement (290 ) — 290 — Payments of long-term debt- external — (220 ) — (220 ) Proceeds from long-term debt - affiliate — — 337 337 Payment of debt issuance costs — (9 ) (9 ) (18 ) Net Cash Provided by (Used in) Financing Activities 268 (193 ) 1,118 1,193 Net Increase (Decrease) in Cash and Cash Equivalents 298 56 (20 ) 334 Cash and Cash Equivalents at Beginning of Period 3 36 20 59 Cash and Cash Equivalents at End of Period $ 301 $ 92 $ — $ 393
Condensed Balance Sheet [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS September 30, 2015 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 50 $ — $ 75 $ — $ — $ 125 Restricted cash — — 69 — — 69 Accounts receivable — trade — 3 101 — — 104 Accounts receivable — affiliate 20 23 8 13 (61 ) 3 Inventory — 2 28 — — 30 Derivative instruments — — — 3 — 3 Notes receivable — — 7 5 (5 ) 7 Prepayments and other current assets — — 24 1 — 25 Total current assets 70 28 312 22 (66 ) 366 Net property, plant and equipment — 61 4,373 — — 4,434 Other Assets Investment in consolidated subsidiaries 1,915 564 — 2,646 (5,125 ) — Equity investments in affiliates — 28 — 525 — 553 Notes receivable — — 11 — — 11 Intangible assets, net — 57 1,320 — — 1,377 Derivative instruments — — — — — — Other non-current assets — — 94 9 — 103 Total other assets 1,915 649 1,425 3,180 (5,125 ) 2,044 Total Assets $ 1,985 $ 738 $ 6,110 $ 3,202 $ (5,191 ) $ 6,844 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) September 30, 2015 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (a) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 229 $ — $ (5 ) $ 224 Accounts payable — 1 20 1 — 22 Accounts payable — affiliate — 6 45 67 (61 ) 57 Derivative instruments — — 41 1 — 42 Accrued expenses and other current liabilities — 1 70 8 — 79 Total current liabilities — 8 405 77 (66 ) 424 Other Liabilities Long-term debt — external — — 3,098 592 — 3,690 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 74 — — 74 Other non-current liabilities — — 53 — — 53 Total non-current liabilities — — 3,225 1,210 — 4,435 Total Liabilities — 8 3,630 1,287 (66 ) 4,859 Commitments and Contingencies Members' Equity Contributed capital 1,728 790 2,402 1,693 (4,885 ) 1,728 Retained earnings (accumulated deficit) 158 (57 ) 83 123 (149 ) 158 Noncontrolling interest 195 — 71 195 (266 ) 195 Accumulated other comprehensive loss (96 ) (3 ) (76 ) (96 ) 175 (96 ) Total Members' Equity 1,985 730 2,480 1,915 (5,125 ) 1,985 Total Liabilities and Members’ Equity $ 1,985 $ 738 $ 6,110 $ 3,202 $ (5,191 ) $ 6,844 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2014 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (a) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 328 $ — $ 78 $ — $ — $ 406 Restricted cash — — 45 — — 45 Accounts receivable — trade — 3 82 — — 85 Accounts receivable — affiliate (256 ) 17 66 268 (95 ) — Inventory — 1 26 — — 27 Notes receivable — — 6 — — 6 Prepayments and other current assets — 1 20 — — 21 Total current assets 72 22 323 268 (95 ) 590 Net property, plant and equipment — 56 4,410 — — 4,466 Other Assets Investment in consolidated subsidiaries 1,664 585 — 2,045 (4,294 ) — Equity investments in affiliates — — — 227 — 227 Notes receivable — — 15 — — 15 Intangible assets, net — 58 1,365 — — 1,423 Derivative instruments — — 2 — — 2 Other non-current assets — — 93 10 — 103 Total other assets 1,664 643 1,475 2,282 (4,294 ) 1,770 Total Assets $ 1,736 $ 721 $ 6,208 $ 2,550 $ (4,389 ) $ 6,826 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2014 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (a) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 214 $ — $ — $ 214 Accounts payable — 1 19 — — 20 Accounts payable — affiliate — 8 99 33 (95 ) 45 Derivative instruments — — 48 — — 48 Accrued expenses and other current liabilities — 2 43 16 — 61 Total current liabilities — 11 423 49 (95 ) 388 Other Liabilities Long-term debt — external — — 3,747 500 — 4,247 Long-term debt — affiliate — — — 337 — 337 Derivative instruments — — 69 — — 69 Other non-current liabilities — — 49 — — 49 Total non-current liabilities — — 3,865 837 — 4,702 Total Liabilities — 11 4,288 886 (95 ) 5,090 Commitments and Contingencies Members' Equity Contributed capital 1,609 747 1,848 1,542 (4,137 ) 1,609 Retained earnings (Accumulated deficit) 185 (34 ) 113 180 (259 ) 185 Accumulated other comprehensive loss (58 ) (3 ) (41 ) (58 ) 102 (58 ) Total Members' Equity 1,736 710 1,920 1,664 (4,294 ) 1,736 Total Liabilities and Members’ Equity $ 1,736 $ 721 $ 6,208 $ 2,550 $ (4,389 ) $ 6,826 (a) All significant intercompany transactions have been eliminated in consolidation.
Condensed Statement of Comprehensive Income [Table Text Block]	For the Three Months Ended September 30, 2015 NRG Yield LLC Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Net Income (Loss) $ 51 $ (7 ) $ 41 $ 44 $ (83 ) $ 46 Other Comprehensive Loss Unrealized loss on derivatives (38 ) — (35 ) (38 ) 73 (38 ) Other comprehensive loss (38 ) — (35 ) (38 ) 73 (38 ) Comprehensive Income (Loss) 13 (7 ) 6 6 (10 ) 8 Less: Comprehensive (loss) income attributable to noncontrolling interests — — 2 (7 ) — (5 ) Comprehensive Income Attributable to NRG Yield LLC $ 13 $ (7 ) $ 4 $ 13 $ (10 ) $ 13 (a) All significant intercompany transactions have been eliminated in consolidation. For the Nine Months Ended September 30, 2015 NRG Yield LLC Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Net Income (Loss) $ 72 $ (25 ) $ 81 $ 76 $ (130 ) $ 74 Other Comprehensive Loss Unrealized loss on derivatives (38 ) — (35 ) (38 ) 73 (38 ) Other comprehensive loss (38 ) — (35 ) (38 ) 73 (38 ) Comprehensive Income (Loss) 34 (25 ) 46 38 (57 ) 36 Less: Comprehensive (loss) income attributable to noncontrolling interests — — (2 ) 4 — 2 Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 34 $ (25 ) $ 48 $ 34 $ (57 ) $ 34 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) For the Three Months Ended September 30, 2014 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Net Income (Loss) $ 51 $ (6 ) $ 50 $ 50 $ (94 ) $ 51 Other Comprehensive Gain (Loss) Unrealized gain (loss) on derivatives 4 — (7 ) 4 3 4 Other comprehensive loss 4 — (7 ) 4 3 4 Comprehensive Income (Loss) $ 55 $ (6 ) $ 43 $ 54 $ (91 ) $ 55 (a) All significant intercompany transactions have been eliminated in consolidation. For the Nine Months Ended September 30, 2014 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Net Income (Loss) $ 126 $ (2 ) $ 118 $ 125 $ (241 ) $ 126 Other Comprehensive Loss Unrealized loss on derivatives (30 ) — (39 ) (30 ) 69 (30 ) Other comprehensive loss (30 ) — (39 ) (30 ) 69 (30 ) Comprehensive Income (Loss) $ 96 $ (2 ) $ 79 $ 95 $ (172 ) $ 96 (a) All significant intercompany transactions have been eliminated in consolidation.
Condensed Income Statement [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Three Months Ended September 30, 2015 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 7 $ 201 $ 1 $ — $ 209 Operating Costs and Expenses Cost of operations — 4 65 — — 69 Depreciation and amortization — 1 49 — — 50 General and administrative — affiliate — — — 2 — 2 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses — 5 114 3 — 122 Operating Income (Loss) — 2 87 (2 ) — 87 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 51 (9 ) — 41 (83 ) — Equity in earnings of unconsolidated affiliates — — — 19 — 19 Other income, net — — 1 — — 1 Loss on debt extinguishment — — (2 ) — — (2 ) Interest expense — — (45 ) (14 ) — (59 ) Total other income (expense), net 51 (9 ) (46 ) 46 (83 ) (41 ) Net Income (Loss) 51 (7 ) 41 44 (83 ) 46 Less: Net income (loss) attributable to noncontrolling interests — — 2 (7 ) — (5 ) Net Income (Loss) Attributable to $ 51 $ (7 ) $ 39 $ 51 $ (83 ) $ 51 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Nine Months Ended September 30, 2015 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 17 $ 580 $ 9 $ — $ 606 Operating Costs and Expenses Cost of operations — 11 200 — — 211 Depreciation and amortization — 3 160 — — 163 General and administrative — affiliate — — — 8 — 8 Acquisition-related transaction and integration costs — — — 2 — 2 Total operating costs and expenses — 14 360 10 — 384 Operating Income (Loss) — 3 220 (1 ) — 222 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 72 (28 ) — 86 (130 ) — Equity in earnings of unconsolidated affiliates — — — 29 — 29 Other income, net — — 2 — — 2 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (132 ) (38 ) — (170 ) Total other income (expense), net 72 (28 ) (139 ) 77 (130 ) (148 ) Net Income (Loss) 72 (25 ) 81 76 (130 ) 74 Less: Net (loss) income attributable to noncontrolling interests — — (2 ) 4 — 2 Net Income (Loss) Attributable to $ 72 $ (25 ) $ 83 $ 72 $ (130 ) $ 72 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Three Months Ended September 30, 2014 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 7 $ 177 $ — $ — $ 184 Operating Costs and Expenses Cost of operations — 4 56 — — 60 Depreciation and amortization — 1 33 — — 34 General and administrative — affiliate — — — 3 — 3 Acquisition-related transaction and integration costs — — — 2 — 2 Total operating costs and expenses — 5 89 5 — 99 Operating Income (Loss) — 2 88 (5 ) — 85 Other Income (Expense) Equity in earnings of consolidated affiliates 50 (8 ) — 52 (94 ) — Equity in earnings of unconsolidated affiliates — — — 11 — 11 Other income, net 1 — — — — 1 Interest expense — — (38 ) (8 ) — (46 ) Total other income (expense), net 51 (8 ) (38 ) 55 (94 ) (34 ) Net Income $ 51 $ (6 ) $ 50 $ 50 $ (94 ) $ 51 (a) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Nine Months Ended September 30, 2014 NRG Yield LLC Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (a) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 19 $ 478 $ — $ — $ 497 Operating Costs and Expenses Cost of operations — 12 161 — — 173 Depreciation and amortization — 3 109 — — 112 General and administrative — affiliate — — — 7 — 7 Acquisition-related transaction and integration costs — — — 2 — 2 Total operating costs and expenses — 15 270 9 — 294 Operating Income (Loss) — 4 208 (9 ) — 203 Other Income (Expense) Equity in earnings of consolidated affiliates 125 (6 ) — 122 (241 ) — Equity in earnings of unconsolidated affiliates — — — 26 — 26 Other income, net 1 — 1 — — 2 Interest expense — — (91 ) (14 ) — (105 ) Total other income (expense), net 126 (6 ) (90 ) 134 (241 ) (77 ) Net Income $ 126 $ (2 ) $ 118 $ 125 $ (241 ) $ 126 (a) All significant intercompany transactions have been eliminated in consolidation.

Nature of Business (Details)

Nature of Business (Details) $ / shares in Units, $ in Millions		Jun. 30, 2015	Jun. 29, 2015USD ($)$ / sharesshares	Jan. 02, 2015USD ($)	Jul. 29, 2014USD ($)shares	Jun. 30, 2014USD ($)MW	Sep. 30, 2015USD ($)MW		Sep. 30, 2014USD ($)		Sep. 30, 2015USD ($)MW		Sep. 30, 2014USD ($)
Nature of Business
Megawatts Thermal Equivalent, Available Under right-to-use Provisions							134				134
Power Generation Capacity, Megawatts	[1]						3,948				3,948
General and administrative — affiliate | $							$ 2		$ 3	[2]	$ 8		$ 7	[2]
Acquisition of businesses, net of cash acquired | $											(37)		(901)	[3]
Proceeds from the issuance of Class C and Class A units | $											$ 599		630	[3]
Distributed Solar
Nature of Business
Power Generation Capacity, Megawatts	[1]						9				9
Wind Farms [Member]
Nature of Business
Power Generation Capacity, Megawatts	[1]						1,389				1,389
Thermal [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Steam and Chilled Water Capacity, Megawatts Thermal Equivalent	[1],[4]						1,310				1,310
Power Generation Capacity, Megawatts	[1]						124				124
Conventional Generation [Member]
Nature of Business
Power Generation Capacity, Megawatts	[1]						1,945				1,945
Utility-Scale Solar
Nature of Business
Power Generation Capacity, Megawatts	[1]						481				481
NRG Yield [Member] | NRG Yield [Member]
Nature of Business
Sale of Stock, Number of Shares Issued in Transaction | shares			28,198,000
NRG Yield LLC
Nature of Business
General and administrative — affiliate | $							$ 0		0		$ 0		0
Acquisition of businesses, net of cash acquired | $											0		0
Proceeds from the issuance of Class C and Class A units | $											$ 599		630
NRG Yield LLC | NRG Yield, Inc. [Member]
Nature of Business
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Voting Interest		44.90%
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest			53.30%
GenConn Middletown | Conventional Generation [Member]
Nature of Business
Equity Method Investment, Ownership Percentage	[5]						50.00%				50.00%
Power Generation Capacity, Megawatts	[1]						95				95
GenConn Devon [Member] | Conventional Generation [Member]
Nature of Business
Equity Method Investment, Ownership Percentage	[5]						50.00%				50.00%
Power Generation Capacity, Megawatts	[1]						95				95
Marsh Landing | Conventional Generation [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						720				720
El Segundo [Member] | Conventional Generation [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						550				550
Walnut Creek [Member] | Conventional Generation [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						485				485
Alpine [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						66				66
Avenal [Member] | Utility-Scale Solar
Nature of Business
Equity Method Investment, Ownership Percentage		49.95%					50.00%	[5]			50.00%	[5]
Power Generation Capacity, Megawatts	[1]						23				23
Avra Valley | Utility-Scale Solar
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						25				25
NRG Solar Blythe LLC [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						21				21
Borrego | Utility-Scale Solar
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						26				26
Roadrunner | Utility-Scale Solar
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						20				20
CVSR [Member] | Utility-Scale Solar
Nature of Business
Equity Method Investment, Ownership Percentage							48.95%				48.95%
Power Generation Capacity, Megawatts	[1],[6]						122				122
Kansas South [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						20				20
TA - High Desert LLC [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						20				20
Desert Sunlight [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership							25.00%				25.00%
AZ DG Solar Projects | Distributed Solar
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						5				5
PFMG DG Solar Projects | Distributed Solar
Nature of Business
Percentage of Ownership							51.00%				51.00%
Power Generation Capacity, Megawatts	[1]						4				4
Alta I [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						150				150
Alta II [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						150				150
Alta III [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						150				150
Alta IV [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						102				102
Alta V [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						168				168
Alta X [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1],[7]						137				137
Alta XI [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1],[7]						90				90
South Trent | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						101				101
Laredo Ridge [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						80				80
Taloga [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						130				130
Pinnacle [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						55				55
Buffalo Bear [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							100.00%				100.00%
Power Generation Capacity, Megawatts	[1]						19				19
Spring Canyon II [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							90.10%				90.10%
Power Generation Capacity, Megawatts	[1]						31				31
Spring Canyon III [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership							90.10%				90.10%
Power Generation Capacity, Megawatts	[1]						26				26
January 2015 Drop Down Assets [Member]
Nature of Business
Acquisition of businesses, net of cash acquired | $				$ (489)
Business Combination, Consideration Transferred, Liabilities Incurred | $				737
Business Acquisition, Consideration Transferred, Working Capital | $				$ 9
June 2014 Drop Down Assets [Member]
Nature of Business
Acquisition of businesses, net of cash acquired | $						$ (357)
Business Combination, Consideration Transferred, Liabilities Incurred | $						612
Business Acquisition, Consideration Transferred, Working Capital | $						$ 8
June 2014 Drop Down Assets [Member] | El Segundo [Member]
Nature of Business
Power Generation Capacity, Megawatts						0
June 2014 Drop Down Assets [Member] | Kansas South [Member]
Nature of Business
Power Generation Capacity, Megawatts						0
June 2014 Drop Down Assets [Member] | TA - High Desert LLC [Member]
Nature of Business
Power Generation Capacity, Megawatts						0
NRG | NRG Yield [Member]
Nature of Business
General and administrative — affiliate | $											$ 8		7
Affiliated Entity [Member]
Nature of Business
General and administrative — affiliate | $							$ 2		$ 3		$ 8		$ 7
Southern California Edison [Member] | Desert Sunlight [Member] | Utility-Scale Solar
Nature of Business
Power Generation Capacity, Megawatts	[1]						63				63
Pacific Gas and Electric [Member] | Desert Sunlight [Member] | Utility-Scale Solar
Nature of Business
Power Generation Capacity, Megawatts	[1]						75				75
Common Class B [Member] | NRG Yield LLC
Nature of Business
Sale of Stock, Percentage of Ownership after Transaction											100.00%
Common Class A [Member]
Nature of Business
Sale of Stock, Number of Shares Issued in Transaction | shares					12,075,000
Proceeds from the issuance of Class C and Class A units | $					$ 630
Common Class A [Member] | NRG Yield LLC
Nature of Business
Sale of Stock, Percentage of Ownership after Transaction											100.00%
Common Class C [Member]
Nature of Business
Sale of Stock, Price Per Share | $ / shares			$ 22
Proceeds from the issuance of Class C and Class A units | $			$ 599
Investment Banking, Advisory, Brokerage, and Underwriting Fees and Commissions | $			$ 21
[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	For thermal energy, net capacity represents MWt for steam or chilled water and excludes 134 MWt available under the right-to-use provisions contained in agreements between two of the Company's thermal facilities and certain of its customers.
[5]	(b) On September 30, 2015, the Company acquired NRG's remaining 0.05% for an immaterial amount.
[6]	Projects are part of tax equity arrangements, as further described in Note 2, Summary of Significant Accounting Policies.
[7]	PPA begins on January 1, 2016.

Summary of Significant Accoun31

Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions	Jun. 30, 2015	May. 08, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	[2]	Sep. 30, 2015	Sep. 30, 2014		Dec. 31, 2014
Summary of Significant Accounting Policies [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption			$ 54					$ 54			$ 61
Noncontrolling interest			195					195
Contributions from noncontrolling interest for Alta Wind X-X1 TE Holdco								119	$ 0	[1]
Comprehensive income			$ (5)			$ 0		$ 2	$ 0	[2]
Dividends Payable, Date Declared			Nov. 4, 2015
Common Stock, Dividends, Per Share, Declared			$ 0.215
Dividends Payable, Date to be Paid			Dec. 15, 2015
Dividends Payable, Date of Record			Dec. 1, 2015
Dividends Per Class A Common Share			$ 0.21	$ 0.20
Spring Canyon [Member]
Summary of Significant Accounting Policies [Line Items]
Percentage of Ownership			90.10%					90.10%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners			9.90%					9.90%
Alta X and XI TE Holdco [Member] | Financial Institutions [Member]
Summary of Significant Accounting Policies [Line Items]
Contributions from noncontrolling interest for Alta Wind X-X1 TE Holdco	$ 119
Spring Canyon [Member] | Financial Institutions [Member]
Summary of Significant Accounting Policies [Line Items]
Noncontrolling interest acquired in Spring Canyon acquisition		$ 74
Common Class A [Member]
Summary of Significant Accounting Policies [Line Items]
Dividends Per Class A Common Share					$ 0.39
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Business Acquisitions Busines32

Business Acquisitions Business Acquisitions - November 2015 Drop Down (Details)		Nov. 03, 2015USD ($)	Sep. 30, 2015USD ($)MW	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)MW	Sep. 30, 2014USD ($)	Nov. 02, 2015USD ($)MW
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		3,948		3,948
November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Combination, Assets Acquired, Current Assets			$ 34,000,000		$ 34,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment			673,000,000		673,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets			179,000,000		179,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets			886,000,000		886,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			193,000,000		193,000,000
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value			289,000,000		289,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Current and Non-Current Liabilities			33,000,000		33,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			226,000,000		226,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net			371,000,000		371,000,000
Business Acquisition, Pro Forma Revenue			225,000,000	$ 200,000,000	660,000,000	$ 561,000,000
Business Acquisition, Pro Forma Net Income(Loss), Including Portion Attributable to Noncontrolling Interest			35,000,000	$ 48,000,000	57,000,000	$ 96,000,000
Subsequent Event [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired							75.00%
Payments to Acquire Businesses, Gross		$ 210,000,000
Number of Facilities							12
Financial Institutions [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value			$ 165,000,000		$ 165,000,000
Financial Institutions [Member] | Subsequent Event [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Taxable Income Allocation, Pre-Flip							99.00%
Taxable Income Allocation, Post-Flip							8.53%
Pre-Flip Point [Member] | Subsequent Event [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Percentage of Cash Available for Distributions							75.00%
Post-Flip Point [Member] | Subsequent Event [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Percentage of Cash Available for Distributions							68.60%
Pre-determined Date Through Flip Point If Flip Has Not Occured [Member] | Financial Institutions [Member] | Subsequent Event [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Percentage of Cash Available for Distributions							100.00%
Wind Farms [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		1,389		1,389
Wind Farms [Member] | Subsequent Event [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW							814
[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015.

Business Acquisitions Busines33

Business Acquisitions Business Acquisitions - Desert Sunlight/Spring Canyon/Fuel Cell (Details)		Jun. 30, 2015USD ($)	May. 08, 2015	Apr. 30, 2015	Aug. 12, 2014USD ($)MW	Sep. 30, 2015MW	Jun. 29, 2015USD ($)	May. 07, 2015
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[1]					3,948
Spring Canyon [Member]
Business Acquisition [Line Items]
Percentage of Ownership						90.10%
Alta Wind Portfolio [Member]
Business Acquisition [Line Items]
Number of Facilities | $					7
Business Acquisition, Percentage of Voting Interests Acquired					100.00%
Power Generation Capacity, Megawatts					947
Payments to Acquire Businesses, Gross | $					$ 923,000,000
Utility-Scale Solar [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[1]					481
Wind Farms [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[1]					1,389
Wind Farms [Member] | Spring Canyon [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired								90.10%
Wind Farms [Member] | Spring Canyon II [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts						34
Wind Farms [Member] | Spring Canyon III [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts						29
Thermal [Member]
Business Acquisition [Line Items]
Percentage of Ownership						100.00%
Power Generation Capacity, Megawatts	[1]					124
Desert Sunlight [Member]
Business Acquisition [Line Items]
Number of Facilities | $							2
Payments to Acquire Equity Method Investments | $		$ 285,000,000
Power Generation Capacity, Megawatts						550
Desert Sunlight [Member] | Utility-Scale Solar [Member]
Business Acquisition [Line Items]
Percentage of Ownership						25.00%
UB Fuel Cell [Member] | Thermal [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts						1.4
Supply Commitment Arrangement [Domain] | Spring Canyon [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life			24 years
Supply Commitment Arrangement [Domain] | Alta Wind Portfolio [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life						22 years
Supply Commitment Arrangement [Domain] | UB Fuel Cell [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life				12 years
Southern California Edison [Member] | Supply Commitment Arrangement [Domain] | Desert Sunlight [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		20 years
Pacific Gas and Electric [Member] | Supply Commitment Arrangement [Domain] | Desert Sunlight [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		25 years
[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015.

Business Acquisitions Busines34

Business Acquisitions Business Acquisitions - January 2015 Drop Downs (Details) $ in Millions		Jan. 02, 2015USD ($)	Sep. 30, 2015USD ($)MW	Sep. 30, 2014USD ($)		Dec. 31, 2014USD ($)
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		3,948
Acquisition of businesses, net of cash acquired			$ (37)	$ (901)	[2]
Total current assets			366			$ 590	[3]
Net property, plant and equipment			4,434			4,466	[3]
Assets, Noncurrent						1,770
Total Assets			6,844			6,826	[3]
Long-term Debt			4,532			4,798
Other current and non-current liabilities						292
Total Liabilities			4,859			5,090	[3]
Net Assets						1,736
January 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Acquisition of businesses, net of cash acquired		$ (489)
Business Acquisition, Consideration Transferred, Working Capital		9
Business Combination, Consideration Transferred, Liabilities Incurred		737
Business Combination, Separately Recognized Transactions, Net Gains and Losses		61
AOCI Including Portion Attributable to Noncontrolling Interest, before Tax		$ 23
Business Acquisition, Pro Forma Revenue				523
Business Acquisition, Pro Forma Net Income(Loss), Including Portion Attributable to Noncontrolling Interest				$ 122
Business Combination, Revenue of Acquiree since Acquisition Date, Actual			106
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual			$ 31
Walnut Creek [Member]
Business Acquisition [Line Items]
Business Combination, Assets Acquired, Current Assets						46
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment						575
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets						57
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets						678
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt						437
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Current and Non-Current Liabilities						62
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities						499
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net						179
Tapestry Wind [Member]
Business Acquisition [Line Items]
Business Combination, Assets Acquired, Current Assets						14
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment						286
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets						61
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets						361
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt						192
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Current and Non-Current Liabilities						5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities						197
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net						164
Laredo Ridge [Member]
Business Acquisition [Line Items]
Business Combination, Assets Acquired, Current Assets						7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment						118
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets						49
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets						174
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt						108
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Current and Non-Current Liabilities						4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities						112
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net						62
Scenario, Previously Reported [Member]
Business Acquisition [Line Items]
Total current assets						523
Net property, plant and equipment						3,487
Assets, Noncurrent						1,603
Total Assets						5,613
Long-term Debt						4,061
Other current and non-current liabilities						221
Total Liabilities						4,282
Net Assets						$ 1,331
Conventional Generation [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		1,945
Conventional Generation [Member] | Walnut Creek [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		485
Wind Farms [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		1,389
Wind Farms [Member] | Pinnacle [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		55
Wind Farms [Member] | Buffalo Bear [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		19
Wind Farms [Member] | Taloga [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		130
Wind Farms [Member] | Laredo Ridge [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		80
[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Business Acquisitions Busines35

Business Acquisitions Business Acquisitions - Alta Wind (Details)		Aug. 12, 2014USD ($)MW	Aug. 05, 2014USD ($)	Jul. 29, 2014USD ($)$ / sharesshares	Dec. 31, 2014USD ($)	Sep. 30, 2015USD ($)MW	Sep. 30, 2014USD ($)
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]					3,948
Business Combination, Consideration Transferred						$ 37,000,000	$ 901,000,000	[2]
Proceeds from the issuance of Class C and Class A units						$ 599,000,000	630,000,000	[2]
Common Class A [Member]
Business Acquisition [Line Items]
Sale of Stock, Number of Shares Issued in Transaction | shares				12,075,000
Share Price | $ / shares				$ 54
Proceeds from the issuance of Class C and Class A units				$ 630,000,000
Alta Wind Portfolio [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents		$ 22,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Cash					$ 0
Number of Facilities		7
Power Generation Capacity, Megawatts | MW		947
Payments to Acquire Businesses, Gross		$ 923,000,000
Business Combination, Consideration Transferred		870,000,000
Business Acquisition, Consideration Transferred, Working Capital		53,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt		1,591,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current and Non-Current Assets		49,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Assets					(2,000,000)
Business Acquisition, Purchase Price Allocation, Other Assets, Adjusted		47,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		1,304,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment					6,000,000
Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment, Adjusted		1,310,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		1,177,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles					(6,000,000)
Business Acquisition, Purchase Price Allocation, Intangible Assets, Other than Goodwill, Adjusted		1,171,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets		2,552,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Total Assets					(2,000,000)
Business Acquisition, Purchase Price Allocation, Assets Acquired, Adjusted		2,550,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Noncurrent Liabilities Longterm Debt					0
Business Acquisition, Purchase Price Allocation, Noncurrent Liabilities, Long-term Debt, Adjusted		1,591,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current and Non-Current Liabilities		38,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Current and Noncurrent Liabilities					(2,000,000)
Business Acquisition, Purchase Price Allocation, Current and Non-current Liabilities, Adjusted		36,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		1,629,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities					(2,000,000)
Business Acquisition, Purchase Price Allocation, Liabilities Assumed, Adjusted		1,627,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		923,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Net Assets Acquired					$ 0
Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net Adjusted		$ 923,000,000
Leasehold Rights [Member] | Alta Wind Portfolio [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life						21 years
Supply Commitment Arrangement [Domain] | Alta Wind Portfolio [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life						22 years
NRG Yield Operating LLC [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred						$ 37,000,000	901,000,000
Proceeds from the issuance of Class C and Class A units						$ 0	$ 0
5.375% Senior Notes due in 2024 [Member]
Business Acquisition [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	[3]					5.375%
5.375% Senior Notes due in 2024 [Member] | NRG Yield Operating LLC [Member]
Business Acquisition [Line Items]
Proceeds from Issuance of Senior Long-term Debt			$ 500,000,000
Debt Instrument, Interest Rate, Stated Percentage			5.375%
[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	As of September 30, 2015, L+ equals 3 month LIBOR plus x%, except for the NRG Marsh Landing term loan, Walnut Creek term loan, and the Revolving Credit Facility where L+ equals 1 month LIBOR plus x% and Kansas South where L+ equals 6 month LIBOR plus x%.

Business Acquisitions Busines36

Business Acquisitions Business Acquisitions - June 2014 Drop Downs (Details) $ in Millions		Jun. 30, 2014USD ($)MW	Sep. 30, 2015USD ($)MW	Sep. 30, 2014USD ($)	[2]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		3,948
Business Combination, Consideration Transferred			$ 37	$ 901
June 2014 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ 357
Business Acquisitions, Consideration Transferred, Purchase Price		349
Business Acquisition, Consideration Transferred, Working Capital		8
Business Combination, Consideration Transferred, Liabilities Incurred		$ 612
El Segundo [Member] | June 2014 Drop Down Assets [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW		0
TA - High Desert LLC [Member] | June 2014 Drop Down Assets [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW		0
Kansas South [Member] | June 2014 Drop Down Assets [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW		0
[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Property, Plant and Equipment37

Property, Plant and Equipment (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment
Property, plant and equipment, gross	$ 4,933	$ 4,804	[1]
Under construction	4	8	[1]
Less accumulated depreciation	(499)	(338)	[1]
Net property, plant and equipment	4,434	4,466	[1]
Support Equipment and Facilities [Member]
Property, Plant and Equipment
Property, plant and equipment, gross	4,837	4,709
Land and improvements
Property, Plant and Equipment
Property, plant and equipment, gross	$ 92	$ 87
Minimum [Member] | Support Equipment and Facilities [Member]
Property, Plant and Equipment
Property, plant and equipment, useful life	2 years
Maximum [Member] | Support Equipment and Facilities [Member]
Property, Plant and Equipment
Property, plant and equipment, useful life	40 years
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Variable Interest Entities Vari

Variable Interest Entities Variable Interest Entities - Alta TE Holdco (Details) - USD ($) $ in Millions	Jun. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	[2]	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Total other assets		$ 2,044			$ 1,770	[1]
Contributions from noncontrolling interests		119	$ 0
Net property, plant and equipment		4,434			4,466	[1]
Total Assets		6,844			6,826	[1]
Total Liabilities		4,859			5,090	[1]
Net Assets					$ 1,736
Alta X and XI TE Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Total other assets		20
Net property, plant and equipment		490
Intangible Assets, Net (Excluding Goodwill)		287
Total Assets		797
Total Liabilities		13
Noncontrolling Interest in Variable Interest Entity		124
Net Assets		$ 660
Alta X and XI TE Holdco [Member] | Financial Institutions [Member]
Schedule of Equity Method Investments [Line Items]
Taxable Income Allocation, Pre-Flip		99.00%
Taxable Income Allocation, Post-Flip		5.00%
Contributions from noncontrolling interests	$ 119
First Year [Member] | Alta X and XI TE Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Cash Available for Distributions		100.00%
Second Year through Flip Point [Member] | Alta X and XI TE Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Cash Available for Distributions		94.34%
Post-Flip Point [Member] | Alta X and XI TE Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Cash Available for Distributions		97.12%
Pre-determined Date Through Flip Point If Flip Has Not Occured [Member] | Alta X and XI TE Holdco [Member] | Financial Institutions [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Cash Available for Distributions		100.00%
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Variable Interest Entities Va39

Variable Interest Entities Variable Interest Entities - DGPV (Details) $ in Millions		May. 08, 2015generatingunitMW	Sep. 30, 2015USD ($)MW	Sep. 30, 2014USD ($)	[2]	Dec. 31, 2014USD ($)	[3]
Schedule of Equity Method Investments [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		3,948
Payments to Acquire Businesses and Interest in Affiliates			$ 335	$ 17
Business Combination, Consideration Transferred			37	$ 901
Equity investments in affiliates			553			$ 227
NRG DGPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Equity investments in affiliates			28
Tax Equity Financed Portfolio of Leases - Community Solar [Member] | NRG DGPV Fund 1 [Member]
Schedule of Equity Method Investments [Line Items]
Power Generation Capacity, Megawatts | MW		11
Remaining Lease Term		20 years
Number of Solar Leases in Portfolio | generatingunit		11
Equity investments in affiliates			17
Tax Equity Financed Portfolio of Leases - Commercial PV [Member] | NRG DGPV Fund 2 [Member]
Schedule of Equity Method Investments [Line Items]
Power Generation Capacity, Megawatts | MW		89
Number of Solar Leases in Portfolio | generatingunit		29
Due to Affiliate			9
Equity investments in affiliates			$ 11
[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Variable Interest Entities Va40

Variable Interest Entities Variable Interest Entities - RPV (Details) $ in Millions		Apr. 09, 2015generatingunitMW	Sep. 30, 2015USD ($)MW	Dec. 31, 2014USD ($)	[2]
Schedule of Equity Method Investments [Line Items]
Power Generation Capacity, Megawatts | MW	[1]		3,948
Equity investments in affiliates			$ 553	$ 227
NRG RPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Equity investments in affiliates			47
Existing Portfolio of Leases [Member] | NRG RPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Number of Solar Leases in Portfolio | generatingunit		2,200
Power Generation Capacity, Megawatts | MW		17
Remaining Lease Term		17 years
Equity investments in affiliates			26
Tax Equity Financed Portfolio of Leases [Member] | NRG RPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Number of Solar Leases in Portfolio | generatingunit		13,000
Power Generation Capacity, Megawatts | MW		90
Equity investments in affiliates			21
Minimum [Member] | Tax Equity Financed Portfolio of Leases [Member] | NRG RPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Remaining Lease Term		17 years
Maximum [Member] | Tax Equity Financed Portfolio of Leases [Member] | NRG RPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Remaining Lease Term		20 years
Equity investments in affiliates			$ 150
[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Variable Interest Entities Va41

Variable Interest Entities Variable Interest Entities - GenConn (Details)		3 Months Ended			9 Months Ended
		Sep. 30, 2015USD ($)facilityMW	Sep. 30, 2014USD ($)		Sep. 30, 2015USD ($)facilityMW	Sep. 30, 2014USD ($)		Jun. 30, 2015	Dec. 31, 2014USD ($)
Schedule of Equity Method Investments [Line Items]
Power Generation Capacity, Megawatts | MW	[1]	3,948			3,948
Equity investments in affiliates		$ 553,000,000			$ 553,000,000				$ 227,000,000	[2]
Long-term Debt		4,532,000,000			4,532,000,000				4,798,000,000
Total operating revenues		209,000,000	$ 184,000,000	[3]	606,000,000	$ 497,000,000	[3]
Operating Income (Loss)		87,000,000	85,000,000	[3]	222,000,000	203,000,000	[3]
Net Income (Loss)		46,000,000	51,000,000	[3],[4]	74,000,000	126,000,000	[3],[5]
Total current assets		366,000,000			366,000,000				590,000,000	[2]
Assets, Noncurrent									1,770,000,000
Current Liabilities		424,000,000			424,000,000				388,000,000	[2]
Total non-current liabilities		$ 4,435,000,000			$ 4,435,000,000				4,702,000,000	[2]
GCE Holding LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		50.00%			50.00%			49.95%
Business Acquisition, Percentage of Voting Interests Acquired		0.05%			0.05%
Equity investments in affiliates		$ 110,000,000			$ 110,000,000
Total operating revenues		21,000,000	18,000,000		61,000,000	62,000,000
Operating Income (Loss)		9,000,000	10,000,000		29,000,000	(30,000,000)
Net Income (Loss)		6,000,000	$ 7,000,000		20,000,000	$ 21,000,000
Total current assets		32,000,000			32,000,000				33,000,000
Assets, Noncurrent		420,000,000			420,000,000				438,000,000
Current Liabilities		16,000,000			16,000,000				20,000,000
Total non-current liabilities		$ 216,000,000			$ 216,000,000				$ 223,000,000
Gen Conn Energy LLC [Member]
Schedule of Equity Method Investments [Line Items]
Power Generation Units, Number | facility		2			2
Power Generation Capacity, Megawatts | MW		190			190
Fixed Rate Notes [Member] | GCE Holding LLC [Member]
Schedule of Equity Method Investments [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 237,000,000			$ 237,000,000
Debt Instrument, Interest Rate, Stated Percentage		4.73%			4.73%
Long-term Debt		$ 220,000,000			$ 220,000,000
Working Capital Facility [Member] | GCE Holding LLC [Member]
Schedule of Equity Method Investments [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 35,000,000			$ 35,000,000
Debt Instrument, Interest Rate, Stated Percentage		1.875%			1.875%
Line of Credit Facility, Fair Value of Amount Outstanding		$ 0			$ 0
[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Variable Interest Entities Va42

Variable Interest Entities Variable Interest Entities - Desert Sunlight (Details)		Jun. 30, 2015	Sep. 30, 2015USD ($)MW	Sep. 30, 2014USD ($)		Sep. 30, 2015USD ($)MW	Sep. 30, 2014USD ($)		Jun. 29, 2015USD ($)	Dec. 31, 2014USD ($)
Schedule of Equity Method Investments [Line Items]
Total operating revenues			$ 209,000,000	$ 184,000,000	[1]	$ 606,000,000	$ 497,000,000	[1]
Operating Income (Loss)			(87,000,000)	(85,000,000)	[1]	(222,000,000)	(203,000,000)	[1]
Net Income (Loss)			46,000,000	51,000,000	[1],[2]	74,000,000	126,000,000	[1],[3]
Total current assets			366,000,000			366,000,000				$ 590,000,000	[4]
Assets, Noncurrent										1,770,000,000
Current Liabilities			424,000,000			424,000,000				388,000,000	[4]
Total non-current liabilities			$ 4,435,000,000			$ 4,435,000,000				4,702,000,000	[4]
Power Generation Capacity, Megawatts | MW	[5]		3,948			3,948
Equity investments in affiliates			$ 553,000,000			$ 553,000,000				227,000,000	[4]
Desert Sunlight [Member]
Schedule of Equity Method Investments [Line Items]
Total operating revenues			73,000,000	48,000,000		170,000,000	102,000,000
Operating Income (Loss)			(51,000,000)	(33,000,000)		(108,000,000)	(58,000,000)
Net Income (Loss)			39,000,000	$ 22,000,000		70,000,000	$ 27,000,000
Total current assets			381,000,000			381,000,000				706,000,000
Assets, Noncurrent			1,508,000,000			1,508,000,000				1,519,000,000
Current Liabilities			91,000,000			91,000,000				436,000,000
Total non-current liabilities			$ 1,141,000,000			$ 1,141,000,000				$ 1,152,000,000
Number of Facilities									2
Power Generation Capacity, Megawatts | MW			550			550
Equity investments in affiliates			$ 281,000,000			$ 281,000,000
Utility-Scale Solar [Member]
Schedule of Equity Method Investments [Line Items]
Power Generation Capacity, Megawatts | MW	[5]		481			481
Utility-Scale Solar [Member] | Desert Sunlight [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Ownership			25.00%			25.00%
Supply Commitment Arrangement [Domain] | Southern California Edison [Member] | Desert Sunlight [Member]
Schedule of Equity Method Investments [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		20 years
Supply Commitment Arrangement [Domain] | Pacific Gas and Electric [Member] | Desert Sunlight [Member]
Schedule of Equity Method Investments [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		25 years
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2015.

Fair Value of Financial Instr43

Fair Value of Financial Instruments Fair Value of Financial Instruments - Balance Sheet Grouping (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt — affiliate	$ 618	$ 337	[1]
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financing Receivable, Net	18	21
Long-term Debt and Capital Lease Obligations, Including Current Maturities	3,914	4,461
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financing Receivable, Net	18	21
Long-term debt — affiliate	542	386
Long-term Debt and Capital Lease Obligations, Including Current Maturities	$ 3,852	$ 4,478
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Fair Value of Financial Instr44

Fair Value of Financial Instruments Fair Value of Financial Instruments - Recurring Fair Value (Details) - USD ($)		Sep. 30, 2015		Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 3,000,000		$ 2,000,000
Derivative Liability, Fair Value, Gross Liability		116,000,000		117,000,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset		3,000,000	[1]	2,000,000	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net				0
Derivative Liability, Fair Value, Gross Liability	[1]	1,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability, Fair Value, Gross Liability		115,000,000	[3]	117,000,000	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net		0		0
Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset				2,000,000
Derivative Liability, Fair Value, Gross Liability		113,000,000		114,000,000
Interest Rate Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]			0
Derivative Liability, Fair Value, Gross Liability	[1]			0
Interest Rate Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset		0	[1]	2,000,000	[2]
Derivative Liability, Fair Value, Gross Liability		113,000,000	[3]	114,000,000	[2]
Commodity Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset		3,000,000
Derivative Liability, Fair Value, Gross Liability		3,000,000		3,000,000
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	0
Derivative Liability, Fair Value, Gross Liability	[1]			1,000,000
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset		3,000,000	[1]	0	[2]
Derivative Liability, Fair Value, Gross Liability		$ 2,000,000	[3]	$ 3,000,000	[2]
[1]	(a) There were no assets or liabilities classified as Level 3 as of September 30, 2015.
[2]	(b) There were no assets or liabilities classified as Level 1 or Level 3 as of December 31, 2014.
[3]	As of September 30, 2015, L+ equals 3 month LIBOR plus x%, except for the NRG Marsh Landing term loan, Walnut Creek term loan, and the Revolving Credit Facility where L+ equals 1 month LIBOR plus x% and Kansas South where L+ equals 6 month LIBOR plus x%.

Fair Value of Financial Instr45

Fair Value of Financial Instruments Fair Value of Financial Instruments - Credit Risk and Derivative FV Measurements (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value Determined Using Valuation Techniques, Percentage	0.00%
Fair Value Assets, Measured on Recurring Basis, Valuation Techniques, Impact of Credit Reserve to Fair Value	$ 3
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure	$ 2,900
Estimated Counterparty Credit Risk Exposure to Certain Counterparties, Period	5 years

Accounting for Derivative Ins46

Accounting for Derivative Instruments and Hedging Activities Accounting for Derivative Instruments and Hedging Activities - FV of Derivatives (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 3	$ 2
Derivative Liability, Fair Value, Gross Liability	116	117
Fair Value of Gross Derivative Assets/(Liabilities), Net	(113)	(115)
Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset	0	0
Derivative Asset, Net Amount	3
Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral	(113)	(115)
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative, Collateral, Obligation to Return Cash	0	0
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	2
Derivative Liability, Fair Value, Gross Liability	103	89
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	3	0
Derivative Liability, Fair Value, Gross Liability	13	28
Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	3
Derivative Liability, Fair Value, Gross Liability	3	3
Fair Value of Gross Derivative Assets/(Liabilities), Net	0	(3)
Derivative Asset, Fair Value, Gross Liability	1
Derivative Liability, Fair Value, Gross Asset	1	0
Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset	0	0
Derivative Asset, Net Amount	2
Derivative Liability, Net Amount	2	3
Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral	0	(3)
Interest Rate Contract Current [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	36	40
Interest Rate Contract Current [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	3	5
Interest Rate Contract Non Current [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	2
Derivative Liability, Fair Value, Gross Liability	67	49
Interest Rate Contract Non Current [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	7	20
Commodity Contract Current [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	3	0
Derivative Liability, Fair Value, Gross Liability	3	3
Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		2
Derivative Liability, Fair Value, Gross Liability	113	114
Fair Value of Gross Derivative Assets/(Liabilities), Net	(113)	(112)
Derivative Asset, Fair Value, Gross Liability		2
Derivative Liability, Fair Value, Gross Asset	0	2
Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset	0	0
Derivative Asset, Net Amount		0
Derivative Liability, Net Amount	113	112
Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral	(113)	(112)
United States of America, Dollars | Interest [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,786	2,817
MMbtu [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 4	$ 2

Accounting for Derivative Ins47

Accounting for Derivative Instruments and Hedging Activities Accounting for Derivative Instruments and Hedging Activities - AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Accumulated Other Comprehensive Loss	$ (96)		$ (96)		$ (58)	$ (58)	$ (31)	$ (35)	$ (1)
Mark-to-market of cash flow hedge accounting contracts	(42)	$ 1	(49)	$ (40)
Losses expected to be realized from OCL during the next 12 months			(18)
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net			0	0
Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative [Line Items]
Reclassified from accumulated OCL to income due to realization of previously deferred amounts	$ 4	$ 3	$ 11	$ 10

Accounting for Derivative Ins48

Accounting for Derivative Instruments and Hedging Activities Accounting for Derivative Instruments and Hedging Activities - Impact on Statement of Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives	$ (6)	$ 0	$ 13	$ (6)
Commodity Contract [Member] | Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives	$ (1)		$ 2

Long-term Debt Long-term Debt -

Long-term Debt Long-term Debt - Debt Table (Details) - USD ($) $ in Millions		May. 29, 2015	Oct. 21, 2014	Jul. 27, 2011	Sep. 30, 2015	Dec. 31, 2014		Dec. 21, 2011	Jul. 27, 2010
Debt Instrument [Line Items]
Long-term debt — affiliate					$ 618	$ 337	[1]
Long-term Debt					4,532	4,798
Current portion of long-term debt — external					224	214	[1]
Long-term Debt, Excluding Current Maturities					4,308	4,584
5.375% Senior Notes due in 2024 [Member]
Debt Instrument [Line Items]
Senior Notes					$ 500	500
Debt Instrument, Interest Rate, Stated Percentage	[2]				5.375%
Intercompany Credit Agreement due 2019 [Member]
Debt Instrument [Line Items]
Long-term debt — affiliate					$ 337	337
Debt Instrument, Interest Rate, Stated Percentage	[2]				3.58%
Intercompany Credit Agreement due 2020 [Member]
Debt Instrument [Line Items]
Long-term debt — affiliate					$ 281	0
Debt Instrument, Interest Rate, Stated Percentage	[2]				3.325%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt	[3]				$ 92	0
Debt Instrument, Description of Variable Rate Basis					1 month LIBOR
Debt Instrument, Basis Spread on Variable Rate					2.75%
Alta Wind I, lease financing arrangement, due 2034 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 255	261
Debt Instrument, Interest Rate, Stated Percentage	[2]				7.015%
Alta Wind II, lease financing arrangement, due 2034 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 200	205
Debt Instrument, Interest Rate, Stated Percentage	[2]				5.696%
Alta Wind III, lease financing arrangement, due 2034 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 208	212
Debt Instrument, Interest Rate, Stated Percentage	[2]				6.067%
Alta Wind IV, lease financing arrangement, due 2034 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 135	138
Debt Instrument, Interest Rate, Stated Percentage	[2]				5.938%
Alta Wind V, lease financing arrangement, due 2035 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 215	220
Debt Instrument, Interest Rate, Stated Percentage	[2]				6.071%
Alta Wind X, due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 0	300
Debt Instrument, Description of Variable Rate Basis					3 month LIBOR
Debt Instrument, Basis Spread on Variable Rate					2.00%
Alta Wind XI, due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 0	191
Debt Instrument, Description of Variable Rate Basis					3 month LIBOR
Debt Instrument, Basis Spread on Variable Rate					2.00%
Alta Realty Investments, due 2031 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 33	34
Debt Instrument, Interest Rate, Stated Percentage	[2]				7.00%
Alta Wind Asset Management, due 2031 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 19	20
Debt Instrument, Description of Variable Rate Basis					3 month LIBOR
Debt Instrument, Basis Spread on Variable Rate					2.375%
West Holdings Credit Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 485	506
Debt Instrument, Description of Variable Rate Basis					1 month LIBOR
West Holdings Credit Agreement due 2023 Tranche A [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis		LIBOR
Debt Instrument, Basis Spread on Variable Rate		1.625%			1.625%
Marsh Landing Term Loan Facility [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 431	464
Walnut Creek Energy, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt				$ 442	$ 363	391
Debt Instrument, Description of Variable Rate Basis					1 month LIBOR
Debt Instrument, Basis Spread on Variable Rate					1.625%
Tapestry Wind LLC due in 2021 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 184	192		$ 214
Debt Instrument, Description of Variable Rate Basis					3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate					1.625%
NRG Energy Center Minneapolis LLC Senior Secured Notes [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 110	121
Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 105	108			$ 75
Debt Instrument, Description of Variable Rate Basis					3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate					1.875%
South Trent Financing Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 62	65
Debt Instrument, Description of Variable Rate Basis					3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate					1.625%
Avra Valley Financing Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 61	63
Debt Instrument, Description of Variable Rate Basis					3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate					1.75%
High Desert Facility [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 54	55
WCEP Holdings, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt				$ 53	$ 46	46
Debt Instrument, Description of Variable Rate Basis			LIBOR	LIBOR	3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate			3.00%	4.00%	3.00%
Roadrunner Financing Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 40	42
Debt Instrument, Description of Variable Rate Basis					3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate					1.625%
Kansas South Facility, due 2031 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 34	35
Debt Instrument, Description of Variable Rate Basis					6-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate					2.00%
NRG Solar Blythe LLC Credit Agreement Due 2028 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 22	22
Debt Instrument, Description of Variable Rate Basis					3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate					1.625%
PFMG Financing Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 30	31
Debt Instrument, Interest Rate, Stated Percentage	[2]				6.00%
NRG Energy Center Princeton LLC, due 2017 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 1	1
Debt Instrument, Interest Rate, Stated Percentage	[2]				5.95%
Project [Domain]
Debt Instrument [Line Items]
Long-term Debt					$ 3,322	3,961
West Holdings Credit Agreement due 2023 Tranche B [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis		LIBOR
Debt Instrument, Basis Spread on Variable Rate		2.25%			2.25%
Marsh Landing Tranche A due December 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis					1 month LIBOR
Debt Instrument, Basis Spread on Variable Rate					1.75%
Marsh Landing Tranche B due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis					1 month LIBOR
Debt Instrument, Basis Spread on Variable Rate					1.875%
Alpine Financing Agreement, due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 156	163
Debt Instrument, Description of Variable Rate Basis					3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate					1.75%
NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					5.95%
NRG Energy Center Minneapolis LLC Senior Secured Notes, due 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					7.25%
Borrego Financing Agreement, due 2024 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 73	$ 75
Debt Instrument, Description of Variable Rate Basis					3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate					2.50%
Borrego Financing Agreement, due 2038 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					5.65%
High Desert Facility, due 2033 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis					3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate					2.50%
TA - High Desert, due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					5.15%
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	As of September 30, 2015, L+ equals 3 month LIBOR plus x%, except for the NRG Marsh Landing term loan, Walnut Creek term loan, and the Revolving Credit Facility where L+ equals 1 month LIBOR plus x% and Kansas South where L+ equals 6 month LIBOR plus x%.
[3]	(b) Applicable rate is determined by the Borrower Leverage Ratio, as defined in the credit agreement.

Long-term Debt Long-term Debt50

Long-term Debt Long-term Debt - Corporate Debt (Details)	Jun. 30, 2015	Sep. 30, 2015USD ($)	Jun. 29, 2015USD ($)$ / shares
3.25% Convertible Notes due 2020 [Member]
Debt Instrument [Line Items]
Convertible Debt			$ 287,500,000
Debt Instrument, Interest Rate, Stated Percentage		3.25%
Debt Instrument, Convertible, Conversion Price | $ / shares			$ 27.50
Debt Instrument, Convertible, Conversion Ratio	36.3636
Debt Instrument, Face Amount			$ 1,000
Convertible Notes Payable [Member]
Debt Instrument [Line Items]
Convertible Debt			$ 281,000,000
Debt Instrument, Interest Rate, Stated Percentage		3.325%
NRG Yield Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 495,000,000
Line of Credit Facility, Fair Value of Amount Outstanding		92,000,000
Letter of Credit [Member] | NRG Yield Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		25,000,000
Scenario, Previously Reported [Member] | NRG Yield Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 450,000,000

Long-term Debt Long-term Debt J

Long-term Debt Long-term Debt January 2015 Drop Downs (Details) - USD ($)	Dec. 17, 2014	Nov. 12, 2014	Oct. 21, 2014	Dec. 21, 2011	Jul. 27, 2011	Sep. 30, 2015	Dec. 31, 2014	Jul. 27, 2010
Debt Instrument [Line Items]
Long-term Debt						$ 4,532,000,000	$ 4,798,000,000
Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Long-term Debt						$ 105,000,000	108,000,000	$ 75,000,000
Proceeds from Issuance of Debt	$ 41,000,000
Debt Instrument, Description of Variable Rate Basis						3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate						1.875%
Debt Issuance Cost	8,000,000
Tapestry Wind LLC due in 2021 [Member]
Debt Instrument [Line Items]
Long-term Debt				$ 214,000,000		$ 184,000,000	192,000,000
Debt Instrument, Description of Variable Rate Basis						3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate						1.625%
Walnut Creek Energy, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 442,000,000	$ 363,000,000	391,000,000
Proceeds from Issuance of Debt			$ 10,000,000
Debt Instrument, Description of Variable Rate Basis						1 month LIBOR
Debt Instrument, Basis Spread on Variable Rate						1.625%
Debt Issuance Cost			$ 4,000,000
WCEP Holdings, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt					$ 53,000,000	$ 46,000,000	$ 46,000,000
Debt Instrument, Description of Variable Rate Basis			LIBOR		LIBOR	3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate			3.00%		4.00%	3.00%
Repayments of Debt			$ 6,000,000
Cash Grant Loan [Member] | Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Long-term Debt								53,000,000
Working Capital Facility [Member] | Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity								3,000,000
Credit Facility, Maximum Borrowing Capacity, Amendment	$ (1,000,000)
Line of Credit Facility, Commitment Fee Percentage	0.50%
Line of Credit Facility, Fair Value of Amount Outstanding						$ 0
Working Capital Facility [Member] | Tapestry Wind LLC due in 2021 [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 8,000,000
Line of Credit Facility, Commitment Fee Percentage				0.75%
Line of Credit Facility, Fair Value of Amount Outstanding						0
Working Capital Facility [Member] | Walnut Creek Energy, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					$ 5,000,000
Line of Credit Facility, Commitment Fee Percentage			0.50%		0.625%
Line of Credit Facility, Fair Value of Amount Outstanding						0
Letter of Credit [Member] | Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity								$ 9,000,000
Credit Facility, Maximum Borrowing Capacity, Amendment	$ 1,000,000
Letters of Credit Outstanding, Amount						10,000,000
Letter of Credit [Member] | Tapestry Wind LLC due in 2021 [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 20,000,000
Letters of Credit Outstanding, Amount						20,000,000
Letter of Credit [Member] | Walnut Creek Energy, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					$ 117,000,000
Letters of Credit Outstanding, Amount						$ 49,000,000
December 17, 2014 to December 31, 2018 [Member] | Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	LIBOR
Debt Instrument, Basis Spread on Variable Rate	1.875%
January 1, 2019 to December 31, 2023 [Member] | Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	LIBOR
Debt Instrument, Basis Spread on Variable Rate	2.125%
January 1, 2024 to March 31, 2028 [Member] | Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	LIBOR
Debt Instrument, Basis Spread on Variable Rate	2.375%
November 12, 2014 to December 20, 2018 [Member] | Tapestry Wind LLC due in 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis		LIBOR
Debt Instrument, Basis Spread on Variable Rate		1.625%
December 21, 2018 to December 31, 2021 [Member] | Tapestry Wind LLC due in 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis		LIBOR
Debt Instrument, Basis Spread on Variable Rate		1.75%
October 21, 2014 to September 30, 2018 [Member] | Walnut Creek Energy, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis			LIBOR
Debt Instrument, Basis Spread on Variable Rate			1.625%
October 1, 2018 to September 30, 2022 [Member] | Walnut Creek Energy, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis			LIBOR
Debt Instrument, Basis Spread on Variable Rate			1.75%
October 1, 2022 to May 31, 2023 [Member] | Walnut Creek Energy, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis			LIBOR
Debt Instrument, Basis Spread on Variable Rate			1.875%
NRG Wind LLC [Member]
Debt Instrument [Line Items]
Distribution Made to Limited Liability Company (LLC) Member, Cash Distributions Paid	$ 33,000,000
Interest Rate Swap [Member] | Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives	75.00%
Interest Rate Swap [Member] | Tapestry Wind LLC due in 2021 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives				90.00%
Derivative, Fixed Interest Rate				2.21%
Derivative, Forward Interest Rate				3.57%
Interest Rate Swap [Member] | Walnut Creek Energy, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives			90.00%		90.00%
Derivative, Fixed Interest Rate			4.0025%		3.54%
Interest Rate Swap [Member] | WCEP Holdings, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Derivative, Fixed Interest Rate					4.00%
Interest Rate Swap [Member] | Laredo Ridge [Member]
Debt Instrument [Line Items]
Derivative, Fixed Interest Rate	2.31%
Minimum [Member] | Interest Rate Swap [Member] | WCEP Holdings, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives			90.00%		90.00%
Maximum [Member] | Interest Rate Swap [Member] | WCEP Holdings, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives			100.00%
WCEP Holdings LLC [Member] | Walnut Creek [Member]
Debt Instrument [Line Items]
Distribution Made to Limited Liability Company (LLC) Member, Cash Distributions Paid			$ 6,000,000

Long-term Debt Long-term Debt52

Long-term Debt Long-term Debt - Alta/Avenal/West Holdings (Details) - USD ($) $ in Millions	Jun. 30, 2015	May. 29, 2015	Mar. 18, 2015	Sep. 30, 2015		Sep. 30, 2014	[2]	Sep. 30, 2015		Sep. 30, 2014	[1]
Debt Instrument [Line Items]
Contributions from noncontrolling interests								$ 119		$ 0
Loss on debt extinguishment				$ (2)		$ 0		$ (9)		$ 0	[2]
West Holdings Credit Agreement due 2023 Tranche A [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis		LIBOR
Debt Instrument, Basis Spread on Variable Rate		1.625%						1.625%
Proceeds from Issuance of Debt		$ 5
West Holdings Credit Agreement due 2023 Tranche B [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis		LIBOR
Debt Instrument, Basis Spread on Variable Rate		2.25%						2.25%
West Holdings Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis								1 month LIBOR
Loss on debt extinguishment								$ (7)
Working Capital Facility [Member] | West Holdings Credit Agreement [Member]
Debt Instrument [Line Items]
Credit Facility, Maximum Borrowing Capacity, Amendment		$ (9)
Financial Institutions [Member] | Alta X and XI TE Holdco [Member]
Debt Instrument [Line Items]
Contributions from noncontrolling interests	$ 119
Interest Rate Swap [Member] | Alta Wind X and Alta Wind XI, due 2020 [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount								$ 17
Avenal [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 43
Proceeds from Debt, Net of Issuance Costs			$ 20
September 22, 2010 to March 18, 2015 [Member] | Avenal [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis			6 month LIBOR
Debt Instrument, Basis Spread on Variable Rate			2.25%
March 18, 2015 to March 17, 2022 [Member] | Avenal [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis			6 month LIBOR
Debt Instrument, Basis Spread on Variable Rate			1.75%
March 18, 2022 to March 17, 2027 [Member] | Avenal [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis			6 month LIBOR
Debt Instrument, Basis Spread on Variable Rate			2.00%
March 18, 2027 through Maturity [Member] | Avenal [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis			6 month LIBOR
Debt Instrument, Basis Spread on Variable Rate			2.25%
September 1, 2017 to August 31, 2020 [Member] | West Holdings Credit Agreement due 2023 Tranche A [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.75%
September 1, 2017 to August 31, 2020 [Member] | West Holdings Credit Agreement due 2023 Tranche B [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.375%
September 1, 2020 through maturity [Member] | West Holdings Credit Agreement due 2023 Tranche A [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.875%
September 1, 2020 through maturity [Member] | West Holdings Credit Agreement due 2023 Tranche B [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.50%
Utility-Scale Solar [Member] | Avenal [Member]
Debt Instrument [Line Items]
Equity Method Investment, Ownership Percentage	49.95%			50.00%	[3]			50.00%	[3]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(b) On September 30, 2015, the Company acquired NRG's remaining 0.05% for an immaterial amount.

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014		Sep. 30, 2015	Sep. 30, 2014		Dec. 31, 2014	[4]
Segment Reporting
Operating revenues	$ 209	$ 184	[1]	$ 606	$ 497	[1]
Cost of operations	69	60		211	173
Depreciation and amortization	50	34	[1]	163	112	[1],[2]
General and administrative — affiliate	2	3	[1]	8	7	[1]
Acquisition-related transaction and integration costs	1	2	[1]	2	2	[1]
Operating income (loss)	87	85	[1]	222	203	[1]
Equity in earnings of unconsolidated affiliates	19	11	[1]	29	26	[1]
Other income, net	1	1	[1]	2	2	[1]
Loss on debt extinguishment	(2)	0	[1]	(9)	0	[1],[2]
Interest expense	(59)	(46)	[1]	(170)	(105)	[1]
Net Income (Loss)	46	51	[1],[3]	74	126	[1],[2]
Total Assets	6,844			6,844			$ 6,826
Conventional Generation [Member]
Segment Reporting
Operating revenues	86	80		247	223
Cost of operations	15	15		51	41
Depreciation and amortization	19	13		61	60
General and administrative — affiliate	0	0		0	0
Acquisition-related transaction and integration costs	0	0		0	0
Operating income (loss)	52	52		135	122
Equity in earnings of unconsolidated affiliates	3	4		10	11
Other income, net	0	0		1	0
Loss on debt extinguishment	0			(7)
Interest expense	(11)	(14)		(36)	(40)
Net Income (Loss)	44	42		103	93
Total Assets	2,132			2,132
Corporate
Segment Reporting
Operating revenues	0	0		0	0
Cost of operations	0	0		0	0
Depreciation and amortization	0	0		0	0
Acquisition-related transaction and integration costs	1	2		2
Operating income (loss)	(3)	(5)		(10)	(9)
Equity in earnings of unconsolidated affiliates	0	0		0	0
Other income, net	0	1		0	1
Loss on debt extinguishment	0			0
Interest expense	(15)	(7)		(38)	(13)
Net Income (Loss)	(18)	(11)		(48)	(21)
Total Assets	64			64
Thermal [Member]
Segment Reporting
Operating revenues	46	48		135	156
Cost of operations	31	32		96	108
Depreciation and amortization	5	5		14	14
General and administrative — affiliate	0	0		0	0
Acquisition-related transaction and integration costs	0	0		0	0
Operating income (loss)	10	11		25	34
Equity in earnings of unconsolidated affiliates	0	0		0	0
Other income, net	0	0		0	0
Loss on debt extinguishment	0			0
Interest expense	(1)	(2)		(5)	(6)
Net Income (Loss)	9	9		20	28
Total Assets	434			434
Renewables
Segment Reporting
Operating revenues	77	56		224	118
Cost of operations	23	13		64	24
Depreciation and amortization	26	16		88	38
General and administrative — affiliate	0	0		0	0
Acquisition-related transaction and integration costs	0	0		0	0
Operating income (loss)	28	27		72	56
Equity in earnings of unconsolidated affiliates	16	7		19	15
Other income, net	1	0		1	1
Loss on debt extinguishment	(2)			(2)
Interest expense	(32)	(23)		(91)	(46)
Net Income (Loss)	11	11		(1)	26
Total Assets	4,214			4,214
Affiliated Entity [Member]
Segment Reporting
General and administrative — affiliate	2	3		8	7
Acquisition-related transaction and integration costs		2			2
Affiliated Entity [Member] | Corporate
Segment Reporting
General and administrative — affiliate	$ 2	$ 3		$ 8	7
Acquisition-related transaction and integration costs					$ 2
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended			12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	[1]	Sep. 30, 2015	Sep. 30, 2014		Dec. 31, 2014
Related Party Transaction
General and administrative — affiliate		$ 2	$ 3		$ 8	$ 7	[1]
GenOn Energy Services LLC [Member]
Related Party Transaction
Due to Affiliate		1			1			$ 4
NRG Yield [Member] | NRG [Member]
Related Party Transaction
Management Services Fee, Increase					1
General and administrative — affiliate					8	7
NRG Yield [Member] | NRG [Member] | Scenario, Plan [Member]
Related Party Transaction
Management Services Fee, Annual					7
NRG Yield, Inc. [Member] | NRG [Member]
Related Party Transaction
Due to Affiliate		5			5
Thermal [Member] | NRG [Member]
Related Party Transaction
Due to Affiliate		30			30			22
Related Party Transaction, Expenses from Transactions with Related Party					21	21
Marsh Landing [Member] | GenOn Energy Services LLC [Member]
Related Party Transaction
Related Party Transaction, Expenses from Transactions with Related Party					11	11
El Segundo [Member] | NRG El Segundo Operations, Inc. [Member]
Related Party Transaction
Due to Affiliate		$ 1			1			1
Related Party Transaction, Expenses from Transactions with Related Party					4	3
Gen Conn Energy LLC [Member] | NRG [Member]
Related Party Transaction
Related Party Transaction, Expenses from Transactions with Related Party					3	$ 5
CVSR [Member] | NRG Energy Services LLC [Member]
Related Party Transaction
Related Party Transaction, Expenses from Transactions with Related Party					$ 4			$ 5
Subsequent Event [Member]
Related Party Transaction
Repayments of Related Party Debt	$ 7
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Condensed Consolidating Finan55

Condensed Consolidating Financial Information CP Income Statement (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Condensed Income Statements, Captions [Line Items]
Total operating revenues	$ 209		$ 184	[1]	$ 606		$ 497	[1]
Operating Costs and Expenses [Abstract]
Cost of operations	69		60	[1]	211		173	[1]
Depreciation and amortization	50		34	[1]	163		112	[1],[2]
General and administrative — affiliate	2		3	[1]	8		7	[1]
Acquisition-related transaction and integration costs	1		2	[1]	2		2	[1]
Total operating costs and expenses	122		99	[1]	384		294	[1]
Operating Income (Loss)	87		85	[1]	222		203	[1]
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates	0		0		0		0
Equity in earnings of unconsolidated affiliates	19		11	[1]	29		26	[1]
Other income, net	1		1	[1]	2		2	[1]
Loss on debt extinguishment	(2)		0	[1]	(9)		0	[1],[2]
Interest expense	(59)		(46)	[1]	(170)		(105)	[1]
Total other income (expense), net	(41)		(34)	[1]	(148)		(77)	[1]
Net Income (Loss)	46		51	[1],[3]	74		126	[1],[2]
Less: Net (loss) income attributable to noncontrolling interests	(5)		0	[1]	2		0	[1]
Net Income (Loss) Attributable to NRG Yield LLC	51		51	[1]	72		126	[1]
NRG Yield LLC [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues	0		0		0		0
Operating Costs and Expenses [Abstract]
Cost of operations	0		0		0		0
Depreciation and amortization	0		0		0		0
General and administrative — affiliate	0		0		0		0
Acquisition-related transaction and integration costs	0		0		0		0
Total operating costs and expenses	0		0		0		0
Operating Income (Loss)	0		0		0		0
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates	51		50		72		125
Equity in earnings of unconsolidated affiliates	0		0		0		0
Other income, net	0		1		0		1
Loss on debt extinguishment	0				0
Interest expense	0		0		0		0
Total other income (expense), net	51		51		72		126
Net Income (Loss)	51		51		72		126
Less: Net (loss) income attributable to noncontrolling interests	0				0
Net Income (Loss) Attributable to NRG Yield LLC	51				72
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues	7		7		17		19
Operating Costs and Expenses [Abstract]
Cost of operations	4		4		11		12
Depreciation and amortization	1		1		3		3
General and administrative — affiliate	0		0		0		0
Acquisition-related transaction and integration costs	0		0		0		0
Total operating costs and expenses	5		5		14		15
Operating Income (Loss)	2		2		3		4
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates	(9)		(8)		(28)		(6)
Equity in earnings of unconsolidated affiliates	0		0		0		0
Other income, net	0		0		0		0
Loss on debt extinguishment	0				0
Interest expense	0		0		0		0
Total other income (expense), net	(9)		(8)		(28)		(6)
Net Income (Loss)	(7)		(6)		(25)		(2)
Less: Net (loss) income attributable to noncontrolling interests	0				0
Net Income (Loss) Attributable to NRG Yield LLC	(7)				(25)
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues	201		177		580		478
Operating Costs and Expenses [Abstract]
Cost of operations	65		56		200		161
Depreciation and amortization	49		33		160		109
General and administrative — affiliate	0		0		0		0
Acquisition-related transaction and integration costs	0		0		0		0
Total operating costs and expenses	114		89		360		270
Operating Income (Loss)	87		88		220		208
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates	0		0		0		0
Equity in earnings of unconsolidated affiliates	0		0		0		0
Other income, net	1		0		2		1
Loss on debt extinguishment	2				9
Interest expense	(45)		(38)		(132)		(91)
Total other income (expense), net	(46)		(38)		(139)		(90)
Net Income (Loss)	41		50		81		118
Less: Net (loss) income attributable to noncontrolling interests	2				(2)
Net Income (Loss) Attributable to NRG Yield LLC	39				83
NRG Yield Operating LLC [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues	1		0		9		0
Operating Costs and Expenses [Abstract]
Cost of operations	0		0		0		0
Depreciation and amortization	0		0		0		0
General and administrative — affiliate	2		3		8		7
Acquisition-related transaction and integration costs	1		2		2		2
Total operating costs and expenses	3		5		10		9
Operating Income (Loss)	(2)		(5)		(1)		(9)
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates	41		52		86		122
Equity in earnings of unconsolidated affiliates	19		11		29		26
Other income, net	0		0		0		0
Loss on debt extinguishment	0				0
Interest expense	(14)		(8)		(38)		(14)
Total other income (expense), net	46		55		77		134
Net Income (Loss)	44		50		76		125
Less: Net (loss) income attributable to noncontrolling interests	(7)				4
Net Income (Loss) Attributable to NRG Yield LLC	51				72
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues	0	[4]	0	[5]	0	[6]	0	[7]
Operating Costs and Expenses [Abstract]
Cost of operations	0	[4]	0	[5]	0	[6]	0	[7]
Depreciation and amortization	0	[4]	0	[5]	0	[6]	0	[7]
General and administrative — affiliate	0	[4]	0	[5]	0	[6]	0	[7]
Acquisition-related transaction and integration costs	0	[4]	0	[5]	0	[6]	0	[7]
Total operating costs and expenses	0	[4]	0	[5]	0	[6]	0	[7]
Operating Income (Loss)	0	[4]	0	[5]	0	[6]	0	[7]
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates	(83)	[4]	(94)	[5]	(130)	[6]	(241)	[7]
Equity in earnings of unconsolidated affiliates	0	[4]	0	[5]	0	[6]	0	[7]
Other income, net	0	[4]	0	[5]	0	[6]	0	[7]
Loss on debt extinguishment	0	[4]			0	[6]
Interest expense	0	[4]	0	[5]	0	[6]	0	[7]
Total other income (expense), net	(83)	[4]	(94)	[5]	(130)	[6]	(241)	[7]
Net Income (Loss)	(83)	[4]	$ (94)	[5]	(130)	[8]	$ (241)	[7]
Less: Net (loss) income attributable to noncontrolling interests	0	[4]			0	[8]
Net Income (Loss) Attributable to NRG Yield LLC	$ (83)	[4]			$ (130)	[6]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	All significant intercompany transactions have been eliminated in consolidation.
[5]	All significant intercompany transactions have been eliminated in consolidation.
[6]	All significant intercompany transactions have been eliminated in consolidation.
[7]	All significant intercompany transactions have been eliminated in consolidation.
[8]	All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Finan56

Condensed Consolidating Financial Information CP Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	$ 46		$ 51	[1],[2]	$ 74		$ 126	[1],[3]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(38)		4	[2]	(38)		(30)	[2]
Other Comprehensive Income (Loss), Net of Tax	(38)		4	[2]	(38)		(30)	[2]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	8		55	[2]	36		96	[2]
Less: Comprehensive (loss) income attributable to noncontrolling interests	(5)		0	[2]	2		0	[2]
Comprehensive Income Attributable to NRG Yield LLC	13		55	[2]	34		96	[2]
NRG Yield LLC [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	51		51		72		126
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(38)		4		(38)		(30)
Other Comprehensive Income (Loss), Net of Tax	(38)		4		(38)		(30)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	13		55		34		96
Less: Comprehensive (loss) income attributable to noncontrolling interests	0				0
Comprehensive Income Attributable to NRG Yield LLC	13				34
Guarantor Subsidiaries [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	(7)		(6)		(25)		(2)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	0		0		0		0
Other Comprehensive Income (Loss), Net of Tax	0		0		0		0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(7)		(6)		(25)		(2)
Less: Comprehensive (loss) income attributable to noncontrolling interests	0				0
Comprehensive Income Attributable to NRG Yield LLC	(7)				(25)
Non-Guarantor Subsidiaries [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	41		50		81		118
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(35)		(7)		(35)		(39)
Other Comprehensive Income (Loss), Net of Tax	(35)		(7)		(35)		(39)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	6		43		46		79
Less: Comprehensive (loss) income attributable to noncontrolling interests	2				(2)
Comprehensive Income Attributable to NRG Yield LLC	4				48
NRG Yield Operating LLC [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	44		50		76		125
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(38)		4		(38)		(30)
Other Comprehensive Income (Loss), Net of Tax	(38)		4		(38)		(30)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	6		54		38		95
Less: Comprehensive (loss) income attributable to noncontrolling interests	(7)				4
Comprehensive Income Attributable to NRG Yield LLC	13				34
Consolidation, Eliminations [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	(83)	[4]	(94)	[5]	(130)	[6]	(241)	[7]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	73	[8]	3	[9]	73	[6]	69	[7]
Other Comprehensive Income (Loss), Net of Tax	73	[8]	3	[9]	73	[6]	69	[7]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(10)	[8]	$ (91)	[9]	(57)	[6]	$ (172)	[7]
Less: Comprehensive (loss) income attributable to noncontrolling interests	0	[8]			0	[6]
Comprehensive Income Attributable to NRG Yield LLC	$ (10)	[8]			$ (57)	[6]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	All significant intercompany transactions have been eliminated in consolidation.
[5]	All significant intercompany transactions have been eliminated in consolidation.
[6]	All significant intercompany transactions have been eliminated in consolidation.
[7]	All significant intercompany transactions have been eliminated in consolidation.
[8]	All significant intercompany transactions have been eliminated in consolidation.
[9]	All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Finan57

Condensed Consolidating Financial Information CP Balance Sheet (Details) - USD ($) $ in Millions		Sep. 30, 2015		Dec. 31, 2014		Sep. 30, 2014		Dec. 31, 2013
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		$ 125		$ 406	[1]	$ 393	[2]	$ 59	[2]
Restricted cash		69		45	[1]
Accounts receivable — trade		104		85	[1]
Accounts receivable — affiliate		3		0	[1]
Inventory		30		27	[1]
Derivative instruments — affiliate		3
Notes receivable		7		6	[1]
Prepayments and other current assets		25		21	[1]
Total current assets		366		590	[1]
Net property, plant and equipment		4,434		4,466	[1]
Investment in consolidated subsidiaries		0		0
Equity investments in affiliates		553		227	[1]
Notes receivable		11		15	[1]
Intangible assets, net		1,377		1,423	[1]
Derivative Asset, Noncurrent		0
Other non-current assets		103		103	[1]
Total other assets		2,044		1,770	[1]
Total Assets		6,844		6,826	[1]
Current portion of long-term debt — external		224		214	[1]
Accounts payable — trade		22		20	[1]
Accounts payable — affiliate		57		45	[1]
Derivative instruments		42		48	[1]
Accrued expenses and other current liabilities		79		61	[1]
Current Liabilities		424		388	[1]
Other Liabilities
Long-term debt — external		3,690		4,247	[1]
Long-term debt — affiliate		618		337	[1]
Derivative instruments		74		69	[1]
Other non-current liabilities		53		49	[1]
Total non-current liabilities		4,435		4,702	[1]
Total Liabilities		$ 4,859		$ 5,090	[1]
Commitments and Contingencies
Contributed capital		$ 1,728		$ 1,609	[1]
Retained earnings		158		185	[1]
Noncontrolling interest		195		0	[1]
Accumulated other comprehensive loss		(96)		(58)	[1]
Total Members' Equity		1,985		1,736	[1]
Total Liabilities and Members’ Equity		6,844		6,826	[1]
NRG Yield LLC [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		50		328		301		3
Restricted cash		0		0
Accounts receivable — trade		0		0
Accounts receivable — affiliate		20		(256)
Inventory		0		0
Derivative instruments — affiliate		0
Notes receivable		0		0
Prepayments and other current assets		0		0
Total current assets		70		72
Net property, plant and equipment		0		0
Investment in consolidated subsidiaries		1,915		1,664
Equity investments in affiliates		0		0
Notes receivable		0		0
Intangible assets, net		0		0
Derivative Asset, Noncurrent		0
Other non-current assets		0		0
Total other assets		1,915		1,664
Total Assets		1,985		1,736
Current portion of long-term debt — external		0		0
Accounts payable — trade		0		0
Accounts payable — affiliate		0		0
Derivative instruments		0		0
Accrued expenses and other current liabilities		0		0
Current Liabilities		0		0
Other Liabilities
Long-term debt — external		0		0
Long-term debt — affiliate		0		0
Derivative instruments		0		0
Other non-current liabilities		0		0
Total non-current liabilities		0		0
Total Liabilities		0		0
Contributed capital		1,728		1,609
Retained earnings		158		185
Noncontrolling interest		195
Accumulated other comprehensive loss		(96)		(58)
Total Members' Equity		1,985		1,736
Total Liabilities and Members’ Equity		1,985		1,736
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0		0
Restricted cash		0		0
Accounts receivable — trade		3		3
Accounts receivable — affiliate		23		17
Inventory		2		1
Derivative instruments — affiliate		0
Notes receivable		0		0
Prepayments and other current assets		0		1
Total current assets		28		22
Net property, plant and equipment		61		56
Investment in consolidated subsidiaries		564		585
Equity investments in affiliates		28		0
Notes receivable		0		0
Intangible assets, net		57		58
Derivative Asset, Noncurrent		0
Other non-current assets		0		0
Total other assets		649		643
Total Assets		738		721
Current portion of long-term debt — external		0		0
Accounts payable — trade		1		1
Accounts payable — affiliate		6		8
Derivative instruments		0		0
Accrued expenses and other current liabilities		1		2
Current Liabilities		8		11
Other Liabilities
Long-term debt — external		0		0
Long-term debt — affiliate		0		0
Derivative instruments		0		0
Other non-current liabilities		0		0
Total non-current liabilities		0		0
Total Liabilities		8		11
Contributed capital		790		747
Retained earnings		(57)		(34)
Noncontrolling interest		0
Accumulated other comprehensive loss		(3)		(3)
Total Members' Equity		730		710
Total Liabilities and Members’ Equity		738		721
Non-Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		75		78		92		36
Restricted cash		69		45
Accounts receivable — trade		101		82
Accounts receivable — affiliate		8		66
Inventory		28		26
Derivative instruments — affiliate		0
Notes receivable		7		6
Prepayments and other current assets		24		20
Total current assets		312		323
Net property, plant and equipment		4,373		4,410
Investment in consolidated subsidiaries		0		0
Equity investments in affiliates		0		0
Notes receivable		11		15
Intangible assets, net		1,320		1,365
Derivative Asset, Noncurrent		0
Other non-current assets		94		93
Total other assets		1,425		1,475
Total Assets		6,110		6,208
Current portion of long-term debt — external		229		214
Accounts payable — trade		20		19
Accounts payable — affiliate		45		99
Derivative instruments		41		48
Accrued expenses and other current liabilities		70		43
Current Liabilities		405		423
Other Liabilities
Long-term debt — external		3,098		3,747
Long-term debt — affiliate		0		0
Derivative instruments		74		69
Other non-current liabilities		53		49
Total non-current liabilities		3,225		3,865
Total Liabilities		3,630		4,288
Contributed capital		2,402		1,848
Retained earnings		83		113
Noncontrolling interest		71
Accumulated other comprehensive loss		(76)		(41)
Total Members' Equity		2,480		1,920
Total Liabilities and Members’ Equity		6,110		6,208
NRG Yield Operating LLC [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0		0		$ 0		$ 20
Restricted cash		0		0
Accounts receivable — trade		0		0
Accounts receivable — affiliate		13		268
Inventory		0		0
Derivative instruments — affiliate		3
Notes receivable		5		0
Prepayments and other current assets		1		0
Total current assets		22		268
Net property, plant and equipment		0		0
Investment in consolidated subsidiaries		2,646		2,045
Equity investments in affiliates		525		227
Notes receivable		0		0
Intangible assets, net		0		0
Derivative Asset, Noncurrent		0
Other non-current assets		9		10
Total other assets		3,180		2,282
Total Assets		3,202		2,550
Current portion of long-term debt — external		0		0
Accounts payable — trade		1		0
Accounts payable — affiliate		67		33
Derivative instruments		1		0
Accrued expenses and other current liabilities		8		16
Current Liabilities		77		49
Other Liabilities
Long-term debt — external		592		500
Long-term debt — affiliate		618		337
Derivative instruments		0		0
Other non-current liabilities		0		0
Total non-current liabilities		1,210		837
Total Liabilities		1,287		886
Contributed capital		1,693		1,542
Retained earnings		123		180
Noncontrolling interest		195
Accumulated other comprehensive loss		(96)		(58)
Total Members' Equity		1,915		1,664
Total Liabilities and Members’ Equity		3,202		2,550
Consolidation, Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0	[3]	0	[4]
Restricted cash		0	[3]	0	[4]
Accounts receivable — trade		0	[3]	0	[4]
Accounts receivable — affiliate		(61)	[3]	(95)	[4]
Inventory		0	[3]	0	[4]
Derivative instruments — affiliate	[3]	0
Notes receivable		(5)	[3]	0	[4]
Prepayments and other current assets		0	[3]	0	[4]
Total current assets		(66)	[3]	(95)	[4]
Net property, plant and equipment		0	[3]	0	[4]
Investment in consolidated subsidiaries		(5,125)	[3]	(4,294)	[4]
Equity investments in affiliates		0	[3]	0	[4]
Notes receivable		0	[3]	0	[4]
Intangible assets, net		0	[3]	0	[4]
Derivative Asset, Noncurrent	[3]	0
Other non-current assets		0	[3]	0	[4]
Total other assets		(5,125)	[3]	(4,294)	[4]
Total Assets		(5,191)	[3]	(4,389)	[4]
Current portion of long-term debt — external		(5)	[5]	0	[6]
Accounts payable — trade		0	[5]	0	[6]
Accounts payable — affiliate		(61)	[5]	(95)	[6]
Derivative instruments		0	[5]	0	[6]
Accrued expenses and other current liabilities		0	[5]	0	[6]
Current Liabilities		(66)	[5]	(95)	[6]
Other Liabilities
Long-term debt — external		0	[5]	0	[6]
Long-term debt — affiliate		0	[5]	0	[6]
Derivative instruments		0	[5]	0	[6]
Other non-current liabilities		0	[5]	0	[6]
Total non-current liabilities		0	[5]	0	[6]
Total Liabilities		(66)	[5]	(95)	[6]
Contributed capital		(4,885)	[5]	(4,137)	[6]
Retained earnings		(149)	[5]	(259)	[6]
Noncontrolling interest	[5]	(266)
Accumulated other comprehensive loss		175	[5]	102	[6]
Total Members' Equity		(5,125)	[5]	(4,294)	[6]
Total Liabilities and Members’ Equity		$ (5,191)	[5]	$ (4,389)	[6]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) All significant intercompany transactions have been eliminated in consolidation.
[4]	All significant intercompany transactions have been eliminated in consolidation.
[5]	All significant intercompany transactions have been eliminated in consolidation.
[6]	All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Finan58

Condensed Consolidating Financial Information CP Cash Flows (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014		Dec. 31, 2014		Dec. 31, 2013
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	$ 269		$ 249	[1]
Intercompany transactions between Yield LLC and subsidiaries	0
Acquisition of businesses, net of cash acquired	(37)		(901)	[1]
Capital expenditures	(16)		(28)	[1]
Increase (Decrease) in Restricted Cash	(24)		20	[1]
Decrease in notes receivable	5		6	[1]
Proceeds from renewable energy grants	0		137	[1]
Net investments in unconsolidated affiliates	(335)		(17)	[1]
Other	0		11	[1]
Net Cash Used in Investing Activities	(896)		(1,108)	[1]
Transfer of funds under intercompany cash management arrangement	0		0
Contributions from noncontrolling interests	119		0	[1]
Proceeds from the issuance of Class C units	599		630	[1]
Payment of distributions	(99)		(72)	[1]
Proceeds from issuance of long-term debt — external	302		579	[1]
Proceeds from issuance of long-term debt — affiliate	281		337	[1]
Payment of debt issuance costs	(7)		(18)	[1]
Payments for long-term debt — external	(849)		(220)	[1]
Net Cash Provided by (Used in) Financing Activities	346		1,193	[1]
Cash and Cash Equivalents, Period Increase (Decrease)	(281)		334	[1]
Cash and cash equivalents	125		393	[1]	$ 406	[2]	$ 59	[1]
NRG Yield LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	0		30
Intercompany transactions between Yield LLC and subsidiaries	(501)
Acquisition of businesses, net of cash acquired	0		0
Capital expenditures	0		0
Increase (Decrease) in Restricted Cash	0		0
Decrease in notes receivable	0		0
Proceeds from renewable energy grants			0
Net investments in unconsolidated affiliates	0		0
Other			0
Net Cash Used in Investing Activities	(501)		0
Transfer of funds under intercompany cash management arrangement	(277)		(290)
Contributions from noncontrolling interests	0
Proceeds from the issuance of Class C units	599		630
Payment of distributions	(99)		(72)
Proceeds from issuance of long-term debt — external	0		0
Proceeds from issuance of long-term debt — affiliate	0		0
Payment of debt issuance costs	0
Payments for long-term debt — external	0		0
Net Cash Provided by (Used in) Financing Activities	223		268
Cash and Cash Equivalents, Period Increase (Decrease)	(278)		298
Cash and cash equivalents	50		301		328		3
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	28
Intercompany transactions between Yield LLC and subsidiaries	0
Acquisition of businesses, net of cash acquired	0
Capital expenditures	0
Increase (Decrease) in Restricted Cash	0
Decrease in notes receivable	0
Net investments in unconsolidated affiliates	(19)
Net Cash Used in Investing Activities	(19)
Transfer of funds under intercompany cash management arrangement	(9)
Contributions from noncontrolling interests	0
Proceeds from the issuance of Class C units	0
Payment of distributions	0
Proceeds from issuance of long-term debt — external	0
Proceeds from issuance of long-term debt — affiliate	0
Payment of debt issuance costs	0
Payments for long-term debt — external	0
Net Cash Provided by (Used in) Financing Activities	(9)
Cash and Cash Equivalents, Period Increase (Decrease)	0
Cash and cash equivalents	0				0
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	183		105
Intercompany transactions between Yield LLC and subsidiaries	0
Acquisition of businesses, net of cash acquired	0		0
Capital expenditures	(16)		(28)
Increase (Decrease) in Restricted Cash	(24)		20
Decrease in notes receivable	5		4
Proceeds from renewable energy grants			137
Net investments in unconsolidated affiliates	0		0
Other			11
Net Cash Used in Investing Activities	(35)		144
Transfer of funds under intercompany cash management arrangement	0		0
Contributions from noncontrolling interests	0
Proceeds from the issuance of Class C units	0		0
Payment of distributions	0		0
Proceeds from issuance of long-term debt — external	5		79
Proceeds from issuance of long-term debt — affiliate	0		0
Payment of debt issuance costs	(6)
Payments for long-term debt — external	(150)		(220)
Net Cash Provided by (Used in) Financing Activities	(151)		(193)
Cash and Cash Equivalents, Period Increase (Decrease)	(3)		56
Cash and cash equivalents	75		92		78		36
NRG Yield Operating LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	58		114
Intercompany transactions between Yield LLC and subsidiaries	501
Acquisition of businesses, net of cash acquired	(37)		(901)
Capital expenditures	0		0
Increase (Decrease) in Restricted Cash	0		0
Decrease in notes receivable	0		2
Proceeds from renewable energy grants			0
Net investments in unconsolidated affiliates	(316)		(17)
Other			0
Net Cash Used in Investing Activities	(341)		(1,252)
Transfer of funds under intercompany cash management arrangement	286		290
Contributions from noncontrolling interests	119
Proceeds from the issuance of Class C units	0		0
Payment of distributions	0		0
Proceeds from issuance of long-term debt — external	297		500
Proceeds from issuance of long-term debt — affiliate	281		337
Payment of debt issuance costs	(1)
Payments for long-term debt — external	(699)		0
Net Cash Provided by (Used in) Financing Activities	283		1,118
Cash and Cash Equivalents, Period Increase (Decrease)	0		(20)
Cash and cash equivalents	0		0		0		$ 20
Consolidation, Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	0	[3]			$ 0	[4]
Drop-down Acquisition [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of businesses, net of cash acquired	(489)		(336)
Drop-down Acquisition [Member] | NRG Yield LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of businesses, net of cash acquired	0		0
Drop-down Acquisition [Member] | Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of businesses, net of cash acquired	0
Drop-down Acquisition [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of businesses, net of cash acquired	0		0
Drop-down Acquisition [Member] | NRG Yield Operating LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of businesses, net of cash acquired	$ (489)		$ (336)
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) All significant intercompany transactions have been eliminated in consolidation.
[4]	All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Finan59

Condensed Consolidating Financial Information PP Income Statement (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Condensed Income Statements, Captions [Line Items]
Total operating revenues	$ 209		$ 184	[1]	$ 606		$ 497	[1]
Operating Costs and Expenses [Abstract]
Cost of operations	69		60	[1]	211		173	[1]
Depreciation and amortization	50		34	[1]	163		112	[1],[2]
General and administrative — affiliate	2		3	[1]	8		7	[1]
Acquisition-related transaction and integration costs	1		2	[1]	2		2	[1]
Total operating costs and expenses	122		99	[1]	384		294	[1]
Operating Income (Loss)	87		85	[1]	222		203	[1]
Equity in earnings (losses) of consolidated affiliates	0		0		0		0
Equity in earnings of unconsolidated affiliates	19		11	[1]	29		26	[1]
Other income, net	1		1	[1]	2		2	[1]
Interest expense	(59)		(46)	[1]	(170)		(105)	[1]
Total other income (expense), net	(41)		(34)	[1]	(148)		(77)	[1]
Net Income (Loss)	46		51	[1],[3]	74		126	[1],[2]
NRG Yield LLC [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues	0		0		0		0
Operating Costs and Expenses [Abstract]
Cost of operations	0		0		0		0
Depreciation and amortization	0		0		0		0
General and administrative — affiliate	0		0		0		0
Acquisition-related transaction and integration costs	0		0		0		0
Total operating costs and expenses	0		0		0		0
Operating Income (Loss)	0		0		0		0
Equity in earnings (losses) of consolidated affiliates	51		50		72		125
Equity in earnings of unconsolidated affiliates	0		0		0		0
Other income, net	0		1		0		1
Interest expense	0		0		0		0
Total other income (expense), net	51		51		72		126
Net Income (Loss)	51		51		72		126
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues	7		7		17		19
Operating Costs and Expenses [Abstract]
Cost of operations	4		4		11		12
Depreciation and amortization	1		1		3		3
General and administrative — affiliate	0		0		0		0
Acquisition-related transaction and integration costs	0		0		0		0
Total operating costs and expenses	5		5		14		15
Operating Income (Loss)	2		2		3		4
Equity in earnings (losses) of consolidated affiliates	(9)		(8)		(28)		(6)
Equity in earnings of unconsolidated affiliates	0		0		0		0
Other income, net	0		0		0		0
Interest expense	0		0		0		0
Total other income (expense), net	(9)		(8)		(28)		(6)
Net Income (Loss)	(7)		(6)		(25)		(2)
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues	201		177		580		478
Operating Costs and Expenses [Abstract]
Cost of operations	65		56		200		161
Depreciation and amortization	49		33		160		109
General and administrative — affiliate	0		0		0		0
Acquisition-related transaction and integration costs	0		0		0		0
Total operating costs and expenses	114		89		360		270
Operating Income (Loss)	87		88		220		208
Equity in earnings (losses) of consolidated affiliates	0		0		0		0
Equity in earnings of unconsolidated affiliates	0		0		0		0
Other income, net	1		0		2		1
Interest expense	(45)		(38)		(132)		(91)
Total other income (expense), net	(46)		(38)		(139)		(90)
Net Income (Loss)	41		50		81		118
NRG Yield Operating LLC [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues	1		0		9		0
Operating Costs and Expenses [Abstract]
Cost of operations	0		0		0		0
Depreciation and amortization	0		0		0		0
General and administrative — affiliate	2		3		8		7
Acquisition-related transaction and integration costs	1		2		2		2
Total operating costs and expenses	3		5		10		9
Operating Income (Loss)	(2)		(5)		(1)		(9)
Equity in earnings (losses) of consolidated affiliates	41		52		86		122
Equity in earnings of unconsolidated affiliates	19		11		29		26
Other income, net	0		0		0		0
Interest expense	(14)		(8)		(38)		(14)
Total other income (expense), net	46		55		77		134
Net Income (Loss)	44		50		76		125
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues	0	[4]	0	[5]	0	[6]	0	[7]
Operating Costs and Expenses [Abstract]
Cost of operations	0	[4]	0	[5]	0	[6]	0	[7]
Depreciation and amortization	0	[4]	0	[5]	0	[6]	0	[7]
General and administrative — affiliate	0	[4]	0	[5]	0	[6]	0	[7]
Acquisition-related transaction and integration costs	0	[4]	0	[5]	0	[6]	0	[7]
Total operating costs and expenses	0	[4]	0	[5]	0	[6]	0	[7]
Operating Income (Loss)	0	[4]	0	[5]	0	[6]	0	[7]
Equity in earnings (losses) of consolidated affiliates	(83)	[4]	(94)	[5]	(130)	[6]	(241)	[7]
Equity in earnings of unconsolidated affiliates	0	[4]	0	[5]	0	[6]	0	[7]
Other income, net	0	[4]	0	[5]	0	[6]	0	[7]
Interest expense	0	[4]	0	[5]	0	[6]	0	[7]
Total other income (expense), net	(83)	[4]	(94)	[5]	(130)	[6]	(241)	[7]
Net Income (Loss)	$ (83)	[4]	$ (94)	[5]	$ (130)	[8]	$ (241)	[7]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	All significant intercompany transactions have been eliminated in consolidation.
[5]	All significant intercompany transactions have been eliminated in consolidation.
[6]	All significant intercompany transactions have been eliminated in consolidation.
[7]	All significant intercompany transactions have been eliminated in consolidation.
[8]	All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Finan60

Condensed Consolidating Financial Information PP Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	$ 46		$ 51	[1],[2]	$ 74		$ 126	[1],[3]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(38)		4	[2]	(38)		(30)	[2]
Other Comprehensive Income (Loss), Net of Tax	(38)		4	[2]	(38)		(30)	[2]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	8		55	[2]	36		96	[2]
NRG Yield LLC [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	51		51		72		126
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(38)		4		(38)		(30)
Other Comprehensive Income (Loss), Net of Tax	(38)		4		(38)		(30)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	13		55		34		96
Guarantor Subsidiaries [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	(7)		(6)		(25)		(2)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	0		0		0		0
Other Comprehensive Income (Loss), Net of Tax	0		0		0		0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(7)		(6)		(25)		(2)
Non-Guarantor Subsidiaries [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	41		50		81		118
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(35)		(7)		(35)		(39)
Other Comprehensive Income (Loss), Net of Tax	(35)		(7)		(35)		(39)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	6		43		46		79
NRG Yield Operating LLC [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	44		50		76		125
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(38)		4		(38)		(30)
Other Comprehensive Income (Loss), Net of Tax	(38)		4		(38)		(30)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	6		54		38		95
Consolidation, Eliminations [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	(83)	[4]	(94)	[5]	(130)	[6]	(241)	[7]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	73	[8]	3	[9]	73	[6]	69	[7]
Other Comprehensive Income (Loss), Net of Tax	73	[8]	3	[9]	73	[6]	69	[7]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ (10)	[8]	$ (91)	[9]	$ (57)	[6]	$ (172)	[7]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	All significant intercompany transactions have been eliminated in consolidation.
[5]	All significant intercompany transactions have been eliminated in consolidation.
[6]	All significant intercompany transactions have been eliminated in consolidation.
[7]	All significant intercompany transactions have been eliminated in consolidation.
[8]	All significant intercompany transactions have been eliminated in consolidation.
[9]	All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Finan61

Condensed Consolidating Financial Information PP Balance Sheet (Details) - USD ($) $ in Millions		Sep. 30, 2015		Dec. 31, 2014		Sep. 30, 2014		Dec. 31, 2013
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		$ 125		$ 406	[1]	$ 393	[2]	$ 59	[2]
Restricted cash		69		45	[1]
Accounts receivable — trade		104		85	[1]
Accounts receivable — affiliate		3		0	[1]
Inventory		30		27	[1]
Derivative instruments — affiliate		3
Notes receivable		7		6	[1]
Prepayments and other current assets		25		21	[1]
Total current assets		366		590	[1]
Net property, plant and equipment		4,434		4,466	[1]
Investment in consolidated subsidiaries		0		0
Equity investments in affiliates		553		227	[1]
Notes receivable		11		15	[1]
Intangible assets, net		1,377		1,423	[1]
Derivative instruments		0		2	[1]
Other non-current assets		103		103	[1]
Total other assets		2,044		1,770	[1]
Total Assets		6,844		6,826	[1]
Current portion of long-term debt — external		224		214	[1]
Accounts payable — trade		22		20	[1]
Accounts payable — affiliate		57		45	[1]
Derivative instruments		42		48	[1]
Accrued expenses and other current liabilities		79		61	[1]
Current Liabilities		424		388	[1]
Other Liabilities
Long-term debt — external		3,690		4,247	[1]
Long-term debt — affiliate		618		337	[1]
Derivative instruments		74		69	[1]
Other non-current liabilities		53		49	[1]
Total non-current liabilities		4,435		4,702	[1]
Total Liabilities		$ 4,859		$ 5,090	[1]
Commitments and Contingencies
Contributed capital		$ 1,728		$ 1,609	[1]
Retained earnings		158		185	[1]
Accumulated other comprehensive loss		(96)		(58)	[1]
Total Members' Equity		1,985		1,736	[1]
Total Liabilities and Members’ Equity		6,844		6,826	[1]
NRG Yield LLC [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		50		328		301		3
Restricted cash		0		0
Accounts receivable — trade		0		0
Accounts receivable — affiliate		20		(256)
Inventory		0		0
Derivative instruments — affiliate		0
Notes receivable		0		0
Prepayments and other current assets		0		0
Total current assets		70		72
Net property, plant and equipment		0		0
Investment in consolidated subsidiaries		1,915		1,664
Equity investments in affiliates		0		0
Notes receivable		0		0
Intangible assets, net		0		0
Derivative instruments				0
Other non-current assets		0		0
Total other assets		1,915		1,664
Total Assets		1,985		1,736
Current portion of long-term debt — external		0		0
Accounts payable — trade		0		0
Accounts payable — affiliate		0		0
Derivative instruments		0		0
Accrued expenses and other current liabilities		0		0
Current Liabilities		0		0
Other Liabilities
Long-term debt — external		0		0
Long-term debt — affiliate		0		0
Derivative instruments		0		0
Other non-current liabilities		0		0
Total non-current liabilities		0		0
Total Liabilities		0		0
Contributed capital		1,728		1,609
Retained earnings		158		185
Accumulated other comprehensive loss		(96)		(58)
Total Members' Equity		1,985		1,736
Total Liabilities and Members’ Equity		1,985		1,736
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0		0
Restricted cash		0		0
Accounts receivable — trade		3		3
Accounts receivable — affiliate		23		17
Inventory		2		1
Derivative instruments — affiliate		0
Notes receivable		0		0
Prepayments and other current assets		0		1
Total current assets		28		22
Net property, plant and equipment		61		56
Investment in consolidated subsidiaries		564		585
Equity investments in affiliates		28		0
Notes receivable		0		0
Intangible assets, net		57		58
Derivative instruments				0
Other non-current assets		0		0
Total other assets		649		643
Total Assets		738		721
Current portion of long-term debt — external		0		0
Accounts payable — trade		1		1
Accounts payable — affiliate		6		8
Derivative instruments		0		0
Accrued expenses and other current liabilities		1		2
Current Liabilities		8		11
Other Liabilities
Long-term debt — external		0		0
Long-term debt — affiliate		0		0
Derivative instruments		0		0
Other non-current liabilities		0		0
Total non-current liabilities		0		0
Total Liabilities		8		11
Contributed capital		790		747
Retained earnings		(57)		(34)
Accumulated other comprehensive loss		(3)		(3)
Total Members' Equity		730		710
Total Liabilities and Members’ Equity		738		721
Non-Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		75		78		92		36
Restricted cash		69		45
Accounts receivable — trade		101		82
Accounts receivable — affiliate		8		66
Inventory		28		26
Derivative instruments — affiliate		0
Notes receivable		7		6
Prepayments and other current assets		24		20
Total current assets		312		323
Net property, plant and equipment		4,373		4,410
Investment in consolidated subsidiaries		0		0
Equity investments in affiliates		0		0
Notes receivable		11		15
Intangible assets, net		1,320		1,365
Derivative instruments				2
Other non-current assets		94		93
Total other assets		1,425		1,475
Total Assets		6,110		6,208
Current portion of long-term debt — external		229		214
Accounts payable — trade		20		19
Accounts payable — affiliate		45		99
Derivative instruments		41		48
Accrued expenses and other current liabilities		70		43
Current Liabilities		405		423
Other Liabilities
Long-term debt — external		3,098		3,747
Long-term debt — affiliate		0		0
Derivative instruments		74		69
Other non-current liabilities		53		49
Total non-current liabilities		3,225		3,865
Total Liabilities		3,630		4,288
Contributed capital		2,402		1,848
Retained earnings		83		113
Accumulated other comprehensive loss		(76)		(41)
Total Members' Equity		2,480		1,920
Total Liabilities and Members’ Equity		6,110		6,208
NRG Yield Operating LLC [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0		0		$ 0		$ 20
Restricted cash		0		0
Accounts receivable — trade		0		0
Accounts receivable — affiliate		13		268
Inventory		0		0
Derivative instruments — affiliate		3
Notes receivable		5		0
Prepayments and other current assets		1		0
Total current assets		22		268
Net property, plant and equipment		0		0
Investment in consolidated subsidiaries		2,646		2,045
Equity investments in affiliates		525		227
Notes receivable		0		0
Intangible assets, net		0		0
Derivative instruments				0
Other non-current assets		9		10
Total other assets		3,180		2,282
Total Assets		3,202		2,550
Current portion of long-term debt — external		0		0
Accounts payable — trade		1		0
Accounts payable — affiliate		67		33
Derivative instruments		1		0
Accrued expenses and other current liabilities		8		16
Current Liabilities		77		49
Other Liabilities
Long-term debt — external		592		500
Long-term debt — affiliate		618		337
Derivative instruments		0		0
Other non-current liabilities		0		0
Total non-current liabilities		1,210		837
Total Liabilities		1,287		886
Contributed capital		1,693		1,542
Retained earnings		123		180
Accumulated other comprehensive loss		(96)		(58)
Total Members' Equity		1,915		1,664
Total Liabilities and Members’ Equity		3,202		2,550
Consolidation, Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0	[3]	0	[4]
Restricted cash		0	[3]	0	[4]
Accounts receivable — trade		0	[3]	0	[4]
Accounts receivable — affiliate		(61)	[3]	(95)	[4]
Inventory		0	[3]	0	[4]
Derivative instruments — affiliate	[3]	0
Notes receivable		(5)	[3]	0	[4]
Prepayments and other current assets		0	[3]	0	[4]
Total current assets		(66)	[3]	(95)	[4]
Net property, plant and equipment		0	[3]	0	[4]
Investment in consolidated subsidiaries		(5,125)	[3]	(4,294)	[4]
Equity investments in affiliates		0	[3]	0	[4]
Notes receivable		0	[3]	0	[4]
Intangible assets, net		0	[3]	0	[4]
Derivative instruments	[4]			0
Other non-current assets		0	[3]	0	[4]
Total other assets		(5,125)	[3]	(4,294)	[4]
Total Assets		(5,191)	[3]	(4,389)	[4]
Current portion of long-term debt — external		(5)	[5]	0	[6]
Accounts payable — trade		0	[5]	0	[6]
Accounts payable — affiliate		(61)	[5]	(95)	[6]
Derivative instruments		0	[5]	0	[6]
Accrued expenses and other current liabilities		0	[5]	0	[6]
Current Liabilities		(66)	[5]	(95)	[6]
Other Liabilities
Long-term debt — external		0	[5]	0	[6]
Long-term debt — affiliate		0	[5]	0	[6]
Derivative instruments		0	[5]	0	[6]
Other non-current liabilities		0	[5]	0	[6]
Total non-current liabilities		0	[5]	0	[6]
Total Liabilities		(66)	[5]	(95)	[6]
Contributed capital		(4,885)	[5]	(4,137)	[6]
Retained earnings		(149)	[5]	(259)	[6]
Accumulated other comprehensive loss		175	[5]	102	[6]
Total Members' Equity		(5,125)	[5]	(4,294)	[6]
Total Liabilities and Members’ Equity		$ (5,191)	[5]	$ (4,389)	[6]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) All significant intercompany transactions have been eliminated in consolidation.
[4]	All significant intercompany transactions have been eliminated in consolidation.
[5]	All significant intercompany transactions have been eliminated in consolidation.
[6]	All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Finan62

Condensed Consolidating Financial Information PP Cash Flows (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014		Dec. 31, 2014		Dec. 31, 2013
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	$ 269		$ 249	[1]
Acquisition of businesses, net of cash acquired	(37)		(901)	[1]
Capital expenditures	(16)		(28)	[1]
Increase (Decrease) in Restricted Cash	(24)		20	[1]
Decrease in notes receivable	5		6	[1]
Proceeds from renewable energy grants	0		137	[1]
Net investments in unconsolidated affiliates	(335)		(17)	[1]
Other	0		11	[1]
Net Cash Used in Investing Activities	(896)		(1,108)	[1]
Capital contributions from NRG			2
Distributions and return of capital to NRG			(45)
Proceeds from the issuance of Class C and Class A units	599		630	[1]
Transfer of funds under intercompany cash management arrangement	0		0
Payment of distributions	(99)		(72)	[1]
Proceeds from issuance of long-term debt — external	302		579	[1]
Payments for long-term debt — external	(849)		(220)	[1]
Proceeds from issuance of long-term debt — affiliate	281		337	[1]
Payment of debt issuance costs			(18)
Net Cash Provided by (Used in) Financing Activities	346		1,193	[1]
Cash and Cash Equivalents, Period Increase (Decrease)	(281)		334	[1]
Cash and cash equivalents	125		393	[1]	$ 406	[2]	$ 59	[1]
NRG Yield LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	0		30
Acquisition of businesses, net of cash acquired	0		0
Capital expenditures	0		0
Increase (Decrease) in Restricted Cash	0		0
Decrease in notes receivable	0		0
Proceeds from renewable energy grants			0
Net investments in unconsolidated affiliates	0		0
Other			0
Net Cash Used in Investing Activities	(501)		0
Capital contributions from NRG			0
Distributions and return of capital to NRG			0
Proceeds from the issuance of Class C and Class A units	599		630
Transfer of funds under intercompany cash management arrangement	(277)		(290)
Payment of distributions	(99)		(72)
Proceeds from issuance of long-term debt — external	0		0
Payments for long-term debt — external	0		0
Proceeds from issuance of long-term debt — affiliate	0		0
Payment of debt issuance costs			0
Net Cash Provided by (Used in) Financing Activities	223		268
Cash and Cash Equivalents, Period Increase (Decrease)	(278)		298
Cash and cash equivalents	50		301		328		3
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	28
Acquisition of businesses, net of cash acquired	0
Capital expenditures	0
Increase (Decrease) in Restricted Cash	0
Decrease in notes receivable	0
Net investments in unconsolidated affiliates	(19)
Net Cash Used in Investing Activities	(19)
Proceeds from the issuance of Class C and Class A units	0
Transfer of funds under intercompany cash management arrangement	(9)
Payment of distributions	0
Proceeds from issuance of long-term debt — external	0
Payments for long-term debt — external	0
Proceeds from issuance of long-term debt — affiliate	0
Net Cash Provided by (Used in) Financing Activities	(9)
Cash and Cash Equivalents, Period Increase (Decrease)	0
Cash and cash equivalents	0				0
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	183		105
Acquisition of businesses, net of cash acquired	0		0
Capital expenditures	(16)		(28)
Increase (Decrease) in Restricted Cash	(24)		20
Decrease in notes receivable	5		4
Proceeds from renewable energy grants			137
Net investments in unconsolidated affiliates	0		0
Other			11
Net Cash Used in Investing Activities	(35)		144
Capital contributions from NRG			2
Distributions and return of capital to NRG			(45)
Proceeds from the issuance of Class C and Class A units	0		0
Transfer of funds under intercompany cash management arrangement	0		0
Payment of distributions	0		0
Proceeds from issuance of long-term debt — external	5		79
Payments for long-term debt — external	(150)		(220)
Proceeds from issuance of long-term debt — affiliate	0		0
Payment of debt issuance costs			(9)
Net Cash Provided by (Used in) Financing Activities	(151)		(193)
Cash and Cash Equivalents, Period Increase (Decrease)	(3)		56
Cash and cash equivalents	75		92		78		36
NRG Yield Operating LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	58		114
Acquisition of businesses, net of cash acquired	(37)		(901)
Capital expenditures	0		0
Increase (Decrease) in Restricted Cash	0		0
Decrease in notes receivable	0		2
Proceeds from renewable energy grants			0
Net investments in unconsolidated affiliates	(316)		(17)
Other			0
Net Cash Used in Investing Activities	(341)		(1,252)
Capital contributions from NRG			0
Distributions and return of capital to NRG			0
Proceeds from the issuance of Class C and Class A units	0		0
Transfer of funds under intercompany cash management arrangement	286		290
Payment of distributions	0		0
Proceeds from issuance of long-term debt — external	297		500
Payments for long-term debt — external	(699)		0
Proceeds from issuance of long-term debt — affiliate	281		337
Payment of debt issuance costs			(9)
Net Cash Provided by (Used in) Financing Activities	283		1,118
Cash and Cash Equivalents, Period Increase (Decrease)	0		(20)
Cash and cash equivalents	0		0		0		$ 20
Consolidation, Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	0	[3]			$ 0	[4]
Drop-down Acquisition [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of businesses, net of cash acquired	(489)		(336)
Drop-down Acquisition [Member] | NRG Yield LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of businesses, net of cash acquired	0		0
Drop-down Acquisition [Member] | Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of businesses, net of cash acquired	0
Drop-down Acquisition [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of businesses, net of cash acquired	0		0
Drop-down Acquisition [Member] | NRG Yield Operating LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of businesses, net of cash acquired	$ (489)		$ (336)
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) All significant intercompany transactions have been eliminated in consolidation.
[4]	All significant intercompany transactions have been eliminated in consolidation.