Lease Obligations - Lessee - Lease Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Lease Cost [Line Items]
Total finance lease costs	$ 6	$ 6
Total operating lease costs	26	28
Total lease costs	32	34
Impairment losses and termination charges	1
Net occupancy and equipment expense
Lease Cost [Line Items]
Amortization of ROU assets	5	5
Interest on long-term debt
Lease Cost [Line Items]
Interest on lease liabilities	1	1
Net occupancy expense
Lease Cost [Line Items]
Operating lease cost	20	20
Short-term lease cost	0	1
Variable lease cost	7	8
Sublease income	$ (1)	$ (1)