Commitments (Other Commitments) (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Other Commitments [Line Items]
Commitments	$ 297,264	$ 295,100
Investments in qualified affordable housing projects	2,700	2,200
Commitments to extend credit
Other Commitments [Line Items]
Commitments	279,635	277,785
Commitments to extend credit | Commercial
Other Commitments [Line Items]
Commitments	210,577	209,864
Commitments to extend credit | Home equity
Other Commitments [Line Items]
Commitments	24,217	24,086
Commitments to extend credit | Credit card
Other Commitments [Line Items]
Commitments	37,215	36,447
Commitments to extend credit | Other
Other Commitments [Line Items]
Commitments	7,626	7,388
Standby letters of credit
Other Commitments [Line Items]
Commitments	11,369	11,251
Standby letters of credit | Remarketing Programs
Other Commitments [Line Items]
Commitments	3,900	3,700
Standby bond purchase agreements
Other Commitments [Line Items]
Commitments	1,095	1,095
Other commitments
Other Commitments [Line Items]
Commitments	$ 5,165	$ 4,969