Investments - Summarized Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule of Equity Method Investments [Line Items]
Net income	$ 884	$ 293	$ 599	$ 1,721
Equity Method Investment, Nonconsolidated Investee, Other
Schedule of Equity Method Investments [Line Items]
Net income			$ 334	$ 88