Investments Accounted for by the Equity Method and Variable Interest Entities (Details) $ in Millions		Dec. 31, 2016 USD ($) MW	Sep. 30, 2016	Dec. 31, 2015 USD ($)	Sep. 30, 2014 MW	Dec. 31, 2009 MW
Investments Accounted for by the Equity Method
Equity investments in affiliates		$ 1,120		$ 1,045
Undistributed earnings by equity investment		$ 101		$ 55
GenConn Energy LLC (a)
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		50.00%
Equity investments in affiliates		$ 106
Petra Nova Parish Holdings [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)			50.00%
Power Generation Capacity, Megawatts | MW					75
Sherbino I Wind Farm LLC
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)						50.00%
Power Generation Capacity, Megawatts | MW						150
Gladstone Power Station (b)
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		37.50%
Equity investments in affiliates		$ 132
Power Generation Capacity, Megawatts | MW		1,613
United States | Avenal Solar Holdings LLC (a)
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	[1]	50.00%
Equity investments in affiliates	[1]	$ (7)
United States | Community Wind North, LLC [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		99.00%
Equity investments in affiliates		$ 21
United States | Desert Sunlight [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	[1]	25.00%
Equity investments in affiliates	[1]	$ 282
United States | Elkhorn Ridge Wind, LLC [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	[1]	47.00%
Equity investments in affiliates	[1]	$ 85
United States | GenConn Energy LLC (a)
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	[1]	50.00%
Equity investments in affiliates	[1]	$ 106
United States | Four Brothers Holdings [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		50.00%
Equity investments in affiliates		$ 208
United States | Granite Mountain Renewables [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		50.00%
Equity investments in affiliates		$ 90
United States | Iron Springs Renewables [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		50.00%
Equity investments in affiliates		$ 48
United States | Midway-Sunset Cogeneration Company [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		50.00%
Equity investments in affiliates		$ 22
United States | Petra Nova Parish Holdings [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		50.00%
Equity investments in affiliates		$ 34
United States | Saguaro Power Company
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		50.00%
Equity investments in affiliates		$ (14)
United States | San Juan Mesa Wind Project, LLC [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	[1]	75.00%
Equity investments in affiliates	[1]	$ 74
United States | Sherbino I Wind Farm LLC
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		50.00%
Equity investments in affiliates		$ 0
United States | Watson Cogeneration Company [Member]
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)		49.00%
Equity investments in affiliates		$ 26
United States | Various [Member]
Investments Accounted for by the Equity Method
Equity investments in affiliates		$ 13
Australia | Gladstone Power Station (b)
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	[2]	37.50%
Equity investments in affiliates	[2]	$ 132
Mechanically-complete solar assets [Member] | SunEdison Utility-Scale Solar and Wind [Member]
Investments Accounted for by the Equity Method
Power Generation Capacity, Megawatts | MW		530
In-development solar assets [Member] | SunEdison Utility-Scale Solar and Wind [Member]
Investments Accounted for by the Equity Method
Power Generation Capacity, Megawatts | MW		71
NRG [Member] | Mechanically-complete solar assets [Member] | SunEdison Utility-Scale Solar and Wind [Member]
Investments Accounted for by the Equity Method
Power Generation Capacity, Megawatts | MW		265

[1] Equity method investments owned by NRG Yield

[2] Gladstone Power Station is located in Australia