Borrowings - Annual Maturities on Borrowings Outstanding (Details) - USD ($) $ in Millions		Sep. 30, 2023	Dec. 31, 2022
FHLB borrowings
Total	[1]	$ 31,800	$ 12,400
Other short-term borrowings
2023		3,148
2024		4,402
Total	[1]	7,550	$ 4,650
2023		15,548
2024		23,802
Total		39,350
Federal Home Loan Bank Advances | Secured Credit Facility
FHLB borrowings
2023		12,400
2024		19,400
Total		$ 31,800

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