Nature of Business Nature of Business (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended											1 Months Ended		0 Months Ended		3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended
	Mar. 31, 2014 MW		Mar. 31, 2013	Mar. 31, 2014 Conventional MW		Mar. 31, 2014 Utility-Scale Solar MW		Mar. 31, 2014 Distributed Solar MW		Mar. 31, 2014 Thermal MW		Jul. 31, 2013 NRG	Jul. 31, 2013 NRG Yield LLC	Jul. 22, 2013 Public Shareholders Common Class A	Jul. 22, 2013 NRG Yield LLC NRG Yield, Inc.	Mar. 31, 2014 NRG Yield LLC NRG Yield, Inc.	Jul. 22, 2013 NRG Yield LLC NRG	Mar. 31, 2014 NRG Yield LLC NRG	Jul. 22, 2013 NRG Yield LLC NRG Class A units of NRG Yield LLC	Jul. 22, 2013 NRG Yield LLC Class A units of NRG Yield LLC	Mar. 31, 2014 GenConn Middletown Conventional MW		Mar. 31, 2014 GenConn Devon Conventional MW		Mar. 31, 2014 Marsh Landing Conventional MW		Mar. 31, 2014 Alpine Utility-Scale Solar MW		Mar. 31, 2014 Avenal [Member] Utility-Scale Solar MW		Mar. 31, 2014 Avra Valley Utility-Scale Solar MW		Mar. 31, 2014 Blythe Utility-Scale Solar MW		Mar. 31, 2014 Borrego Utility-Scale Solar MW		Mar. 31, 2014 Roadrunner Utility-Scale Solar MW		Mar. 31, 2014 CVSR Utility-Scale Solar MW		Mar. 31, 2014 AZ DG Solar Projects Distributed Solar MW		Mar. 31, 2014 PFMG DG Solar Projects Distributed Solar MW		Mar. 31, 2014 South Trent Wind MW		May 05, 2014 Subsequent Event [Member]
Nature of Business
Document Period End Date	Mar. 31, 2014
General and administrative — affiliate	$ 2		$ 2
Sale of Stock, Number of Shares Issued in Transaction														22,511,250
Sale of Stock, Number of Shares Acquired in Transaction																			19,011,250	3,500,000
Payments to Acquire Interest in Subsidiaries and Affiliates												395	73
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest															34.50%	34.50%	65.50%	65.50%
Percentage of Ownership										100.00%											49.95%		49.95%		100.00%		100.00%		49.95%		100.00%		100.00%		100.00%		100.00%		48.95%	[1]	100.00%		51.00%		100.00%
Power Generation Capacity (in MWs)	1,447	[2]		910	[2]	303	[2]	10	[2]	123	[2]										95	[2]	95	[2]	720	[2]	66	[2]	23	[2]	25	[2]	21	[2]	26	[2]	20	[2]	122	[1],[2]	5	[2]	5	[2]	101	[2]
Steam and Chilled Water Capacity, Megawatts Thermal Equivalent										1,346	[1],[2]
Business Acquisitions, Consideration Transferred, Purchase Price																																															$ 349

[1] (b) For thermal energy, net capacity represents MWt for steam or chilled water and excludes 118 MWt which is available under the right-to-use provisions contained in agreements between two of NRG Yield Inc.'s thermal facilities and certain of their customers

[2] Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of March 31, 2014.