Investments Accounted for by the Equity Method and Variable Interest Entities - Summary of Equity Method Investments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Investments Accounted for by the Equity Method
Equity investments in affiliates	$ 157	$ 346
Difference between carrying value and underlying net assets	116
Undistributed earnings from equity investment	$ 33	$ 30
Gladstone
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	37.50%
Equity investments in affiliates	$ 127
Ivanpah Master Holdings, LLC
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	54.50%
Equity investments in affiliates	$ 4
Watson Cogeneration Company
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	49.00%
Equity investments in affiliates	$ 14
Midway-Sunset Cogeneration Company
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	50.00%
Equity investments in affiliates	$ 12
Petra Nova Parish Holdings
Investments Accounted for by the Equity Method
Economic interest in equity method investments (as a percent)	50.00%
Petra Nova Parish Holdings | Other Noncurrent Liabilities
Investments Accounted for by the Equity Method
Equity investments in affiliates	$ (16)