Derivative Instruments (Details 5) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net		$ (11)	$ (6)	$ (15)	$ (18)
Depreciation expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1],[2]	4	0	4	0
Interest Rate Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1],[2]	(15)	(6)	(19)	(18)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[3]	(15)	(11)	(26)	(22)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Depreciation expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1],[2],[3]	(4)	0	(4)	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Interest Rate Hedging Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	[1],[2],[3]	$ (11)	$ (11)	$ (22)	$ (22)

[1] We did not record any material gain (loss) on hedge ineffectiveness related to our interest rate hedging instruments designated as cash flow hedges during the three and six months ended June 30, 2017 and 2016.

[2] We recorded an income tax expense of $2 million in losses for each of the three and six months ended June 30, 2017 and nil for each of the three and six months ended June 30, 2016, in AOCI related to our cash flow hedging activities.

[3] Cumulative cash flow hedge losses attributable to Calpine, net of tax, remaining in AOCI were $107 million and $90 million at June 30, 2017 and December 31, 2016, respectively. Cumulative cash flow hedge losses attributable to the noncontrolling interest, net of tax, remaining in AOCI were $8 million and $8 million at June 30, 2017 and December 31, 2016, respectively.