CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Revenues
Total operating revenues	$ 26,989	$ 9,093	$ 9,821
Operating Costs and Expenses
Cost of operations (excluding depreciation and amortization shown below)	20,482	6,540	7,303
Depreciation and amortization	785	435	373
Impairment losses	544	75	5
Selling, general and administrative costs	1,293	810	760
Provision for credit losses	698	108	95
Acquisition-related transaction and integration costs	93	23	2
Total operating costs and expenses	23,895	7,991	8,538
Gain on sale of assets	247	3	7
Operating Income	3,341	1,105	1,290
Other Income/(Expense)
Equity in earnings of unconsolidated affiliates	17	17	2
Impairment losses on investments	0	(18)	(108)
Other income, net	63	67	66
Loss on debt extinguishment	(77)	(9)	(51)
Interest expense	(485)	(401)	(413)
Total other expense	(482)	(344)	(504)
Income from Continuing Operations Before Income Taxes	2,859	761	786
Income tax expense/(benefit)	672	251	(3,334)
Income from Continuing Operations	2,187	510	4,120
Income from discontinued operations, net of income tax	0	0	321
Net Income	2,187	510	4,441
Less: Net income attributable to redeemable noncontrolling interest	0	0	3
Net Income Attributable to NRG Energy, Inc.	$ 2,187	$ 510	$ 4,438
Income Per Share Attributable to NRG Energy, Inc. Common Stockholders
Weighted average number of common shares outstanding — basic (in shares)	245,000,000	245,000,000	262,000,000
Income from continuing operations per weighted average common share —basic (in usd per share)	$ 8.93	$ 2.08	$ 15.71
Income/(loss) from discontinued operations per weighted average common share — basic (in usd per share)	0	0	1.23
Net Income per Weighted Average Common Share - Basic (in usd per share)	$ 8.93	$ 2.08	$ 16.94
Weighted average number of common shares outstanding — diluted (in shares)	245,000,000	246,000,000	264,000,000
Income from continuing operations per weighted average common share — diluted (in usd per share)	$ 8.93	$ 2.07	$ 15.59
Income/(loss) from discontinued operations per weighted average common share — diluted (in usd per share)	0	0	1.22
Net Income per Weighted Average Common Share - Diluted (in usd per share)	$ 8.93	$ 2.07	$ 16.81