Consolidated Condensed Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 163	$ 270	$ 293	$ 450
Cash flow hedging activities:
Loss on cash flow hedges before reclassification adjustment for cash flow hedges realized in net income	(22)	(29)	(132)	(52)
Reclassification adjustment for (gain) loss on cash flow hedges realized in net income	25	(3)	31	(5)
Foreign currency translation gain (loss)	3	1	(4)	3
Income tax benefit (expense)	(1)	1	2	1
Other comprehensive income (loss)	5	(30)	(103)	(53)
Comprehensive income	168	240	190	397
Comprehensive (income) attributable to the noncontrolling interest	0	(3)	(2)	(8)
Comprehensive income attributable to Calpine	$ 168	$ 237	$ 188	$ 389

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