Income Taxes - Income Tax Expense (Benefit) by Current and Deferred (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Federal
Current	$ 0	$ 12	$ 0
Deferred	162	186	199
State and local
Current	22	4	(9)
Deferred	42	41	28
Foreign
Current	19	17	30
Deferred	(24)	(5)	(52)
Total income tax expense	$ 221	$ 255	$ 196