Revenue - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract liabilities	$ 130	$ 137
Contract liability amortization period (months)	30 months
Deferred incremental direct costs, amortization period (years)	4 years
Customer contract costs, net	$ 145	163
Amortization period of incremental direct costs of obtaining a contract (years)	4 years
Contract Fulfillment Costs and Inducements
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Capitalized contract costs, deferred	$ 13	13
Amortization of capitalized contract fulfillment and inducement costs	$ 4	$ 5	$ 5