Borrowings - Annual Maturities on Borrowings Outstanding (Details) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
FHLB borrowings	[1]	$ 26,400	$ 12,400
Other short-term borrowings	[1]	6,553	$ 4,650
Total		32,953
Federal Home Loan Bank Advances | Secured Debt
Debt Instrument [Line Items]
FHLB borrowings		$ 26,400

[1] Certain prior year amounts have been reclassified to conform to the current year presentation. See Note 1 for additional information.