Commitments (Other Commitments) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Other Commitments [Line Items]
Commitments	$ 284,275	$ 284,768
Liability Related To Investments In Low Income Housing Tax Credits	2,100	2,100
Commitments to extend credit
Other Commitments [Line Items]
Commitments	268,087	268,391
Commitments to extend credit | Commercial
Other Commitments [Line Items]
Commitments	201,828	203,080
Commitments to extend credit | Home equity
Other Commitments [Line Items]
Commitments	24,170	23,970
Commitments to extend credit | Credit card
Other Commitments [Line Items]
Commitments	34,547	33,978
Commitments to extend credit | Other
Other Commitments [Line Items]
Commitments	7,542	7,363
Standby letters of credit
Other Commitments [Line Items]
Commitments	10,651	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	1,194	1,078
Other commitments
Other Commitments [Line Items]
Commitments	$ 4,343	$ 4,386