Leases - Lease costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Lease cost
Operating lease cost	$ 162	$ 145
Finance lease cost:
Amortization of right of use assets	17	9
Interest on lease liabilities	5	4
Variable lease cost	20	8
Short-term lease cost	27	25
Sublease income	(8)	(6)
Total lease cost	$ 223	$ 185