CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 202	$ 96	$ 684	$ 329
Other Comprehensive (Loss)/Income
Unrealized gain on derivatives	0	5	0	19
Foreign currency translation adjustments	(1)	(4)	0	(6)
Available-for-sale securities	1	1	1	1
Defined benefit plans	(3)	(1)	(6)	(2)
Other comprehensive (loss)/income	(3)	1	(5)	12
Comprehensive Income	199	97	679	341
Less: Comprehensive income/(loss) attributable to noncontrolling interest and redeemable noncontrolling interest	1	26	1	(12)
Comprehensive Income/(Loss) Attributable to NRG Energy, Inc.	$ 198	$ 71	$ 678	$ 353

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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