Income Taxes - Income (Loss) Before Income Taxes and Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income before income tax expense:
Domestic	$ 1,160	$ 328	$ 432
Foreign	1,456	1,305	1,445
Income before income tax expense	2,616	1,633	1,877
Current:
Federal	206	136	(208)
State	92	24	(15)
Foreign	218	323	280
Total current	516	483	57
Deferred:
Federal	(84)	781	(153)
State	(10)	(16)	106
Foreign	(3)	(1,118)	19
Total deferred	(97)	(353)	(28)
Income tax expense	$ 419	$ 130	$ 29