Condensed Consolidated Statements of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating Revenues
Total operating revenues	$ 1,862	$ 1,995
Operating Costs and Expenses
Cost of operations	1,573	1,324
Depreciation and amortization	230	205
Selling, general and administrative	221	143
Development costs	8	9
Total operating costs and expenses	2,032	1,681
Operating (Loss)/Income	(170)	314
Other Income/(Expense)
Equity in earnings/(losses) of unconsolidated affiliates	8	(2)
Impairment charge on investment	(1)	(481)
Other income, net	2	5
Loss on debt extinguishment	0	(28)
Interest expense	(165)	(173)
Total other expense	(156)	(679)
Loss Before Income Taxes	(326)	(365)
Income tax benefit	(120)	(105)
Net loss	(206)	(260)
Less: Net income attributable to noncontrolling interest	1	0
Net Loss attributable to NRG Energy, Inc.	(207)	(260)
Dividends for preferred shares	2	2
Loss available for common stockholders	$ (209)	$ (262)
Loss per share attributable to NRG Energy, Inc. Common Stockholders
Weighted average number of common shares outstanding — basic and diluted	228	247
Net loss per weighted average common share, basic and diluted	$ (0.92)	$ (1.06)