Income Taxes (Details) (USD $) In Millions, unless otherwise specified	2 Months Ended	3 Months Ended		0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended
	Sep. 30, 2013	Mar. 31, 2014	Mar. 31, 2013	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
Income Taxes
Document Period End Date		Mar. 31, 2014
Income before income taxes		$ 21	$ 11
Income tax expense		3	0
Effective tax rate (as a percent)		14.30%	0.00%
Statutory income tax rate (as a percent)		35.00%
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest				34.50%	34.50%	65.50%	65.50%
Adjustment to additional paid-in capital for tax basis differences	$ 153