Income Taxes - Income Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. income	$ 2,280	$ 1,599	$ 1,421
Non-U.S. income	275	339	289
Income before income taxes and equity income	$ 2,555	$ 1,938	$ 1,710