Revenue - Contract Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Incremental direct costs of obtaining a contract	$ 61	$ 62	$ 78
Amortization of incremental direct costs	$ 73	$ 81	$ 88