Leases - Components of Lease Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Components of lease expense
Total lease cost	$ 72	$ 69	$ 68
General and administrative expenses
Components of lease expense
Operating lease costs	57	57	58
Amortization of ROU assets	13	10	8
Interest and debt expense
Components of lease expense
Finance lease interest expense	$ 2	$ 2	$ 2