Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net loss	$ (125)	$ (9)
Cash flow hedging activities:
Gain on cash flow hedges before reclassification adjustment for cash flow hedges realized in net loss	4	10
Reclassification adjustment for (gain) loss on cash flow hedges realized in net loss	9	(10)
Foreign currency translation gain (loss)	(2)	3
Income tax benefit	1	2
Other comprehensive income	12	5
Comprehensive loss	(113)	(4)
Comprehensive (income) attributable to the noncontrolling interest	0	0
Comprehensive loss attributable to Calpine	$ (113)	$ (4)