Variable Interest Entities and Unconsolidated Investments (Unconsolidated VIEs) (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Equity Method Investments Included on Balance Sheet [Abstract]
Equity Method Investments		$ 70	$ 76
Greenfield [Member]
Equity Method Investments Included on Balance Sheet [Abstract]
Equity Method Investments	[1]	$ 66	55
Equity Method Investment, Ownership Percentage	[1]	50.00%
Whitby [Member]
Equity Method Investments Included on Balance Sheet [Abstract]
Equity Method Investments	[2]	$ 0	15
Equity Method Investment, Ownership Percentage	[2]	0.00%
Calpine Receivables [Member]
Equity Method Investments Included on Balance Sheet [Abstract]
Equity Method Investments		$ 4	$ 6
Equity Method Investment, Ownership Percentage		100.00%

[1] Includes our share of accumulated other comprehensive income/loss related to interest rate hedging instruments associated with our unconsolidated subsidiary Greenfield LP’s debt.

[2] On November 20, 2019, we sold our 50% interest in Whitby to a third party and recorded a gain on sale of assets, net of approximately $5 million.