Income Taxes - Components of United States and Foreign Tax (Benefit) Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ (5)	$ 0	$ (15)
Foreign	95	134	188
State	(3)	17	(1)
Current income tax expense (benefit)	87	151	172
Deferred:
Federal	63	133	120
Foreign	(31)	153	6
State	(9)	37	5
Deferred income tax expense (benefit)	23	323	131
United States and Foreign Tax Expense	$ 110	$ 474	$ 303