Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Tax benefit attributable to enactment of TCJA			$ 32
GILTI, percent	0.20%	0.30%	0.20%
Undistributed indefinitely reinvested earnings of certain foreign subsidiaries	$ 5,800
Unrecognized tax benefits	308	$ 149	$ 108	$ 94
Unrecognized tax benefits that would impact effective tax rate	294	140	100
Maximum estimated income tax expense change in unrecognized tax benefit in the next 12 months	104
Interest expense for tax examination	6	5	1
Interest accrued for tax examination	$ 14	$ 10	$ 8