Lease Obligations - Lessee - Lease Assets and Lease Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Leases [Abstract]
Operating lease ROU assets	$ 525	$ 511
Finance lease ROU assets	153	126
Total ROU assets	678	637
Operating lease liabilities	609	601
Finance lease liabilities	166	134
Total lease liabilities	$ 775	$ 735
Operating lease right-of-use assets [Extensible List]	Other assets	Other assets
Finance lease, right-of-use assets [Extensible List]	Bank premises and equipment (includes $24 and $19 held for sale)	Bank premises and equipment (includes $24 and $19 held for sale)
Operating lease liabilities [Extensible List]	Accrued Liabilities [Member]	Accrued Liabilities [Member]
Finance lease liabilities [Extensible List]	Long-term debt	Long-term debt
Operating lease right of use asset, accumulated amortization	$ 328	$ 292
Finance lease right of use asset, accumulated amortization	$ 58	$ 77