Leases - Components of Lease Cost and Rent Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Leases [Abstract]
Operating lease cost	$ 51	$ 48
Short-term rent expense	23	25
Variable lease cost	4	6
Sublease income	(1)	(1)
Total operating lease cost	77	78
Finance lease cost:
Amortization of right-of-use assets	3	3
Interest on finance lease liabilities	4	1
Total finance lease cost	$ 7	$ 4