Lease Obligations - Lessee - Lease Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Lease Cost [Line Items]
Total finance lease costs	$ 22	$ 14	$ 7
Total operating lease costs	110	137	124
Total lease costs	132	151	131
Impairment losses and termination charges	3	8	15
Net occupancy and equipment expense
Lease Cost [Line Items]
Amortization of ROU assets	18	11	6
Interest on long-term debt
Lease Cost [Line Items]
Interest on lease liabilities	4	3	1
Net occupancy expense
Lease Cost [Line Items]
Operating lease cost	80	110	96
Short-term lease cost	2	1	1
Variable lease cost	31	29	30
Sublease income	(3)	(3)	(3)
Impairment losses and termination charges	$ 3	$ 8	$ 15