Lease Obligations - Lessee - Lease Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Lease costs:
Total finance lease costs	$ 24	$ 24	$ 22
Total operating lease costs	116	110	110
Total lease costs	140	134	132
Impairment losses and termination charges	2	2	3
Net occupancy and equipment expense
Lease costs:
Amortization of ROU assets	19	19	18
Interest on long-term debt
Lease costs:
Interest on lease liabilities	5	5	4
Net occupancy expense
Lease costs:
Operating lease cost	87	84	80
Short-term lease cost	2	1	2
Variable lease cost	29	28	31
Sublease income	(2)	(3)	(3)
Impairment losses and termination charges	$ 2	$ 2	$ 3