Commitments (Other Commitments) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Other Commitments [Line Items]
Commitments	$ 290,376	$ 284,768
Investments in qualified affordable housing projects	2,200	2,100
Commitments to extend credit
Other Commitments [Line Items]
Commitments	273,664	268,391
Commitments to extend credit | Commercial
Other Commitments [Line Items]
Commitments	205,924	203,080
Commitments to extend credit | Home equity
Other Commitments [Line Items]
Commitments	24,161	23,970
Commitments to extend credit | Credit card
Other Commitments [Line Items]
Commitments	36,003	33,978
Commitments to extend credit | Other
Other Commitments [Line Items]
Commitments	7,576	7,363
Standby letters of credit
Other Commitments [Line Items]
Commitments	10,826	10,913
Standby letters of credit | Remarketing Programs
Other Commitments [Line Items]
Commitments	3,500	3,900
Standby bond purchase agreements
Other Commitments [Line Items]
Commitments	1,055	1,078
Other commitments
Other Commitments [Line Items]
Commitments	$ 4,831	$ 4,386