Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Effective income tax rate (as a percent)	19.90%	22.80%	21.70%	21.60%
Unrecognized tax benefits	$ 143		$ 143		$ 121
Accrued interest and penalties associated with unrecognized tax benefits	27		27		$ 24
Reduction of unrecognized tax benefits is reasonably possible	$ 18		$ 18