Borrowings - Short-term Borrowings (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Short-term Debt [Line Items]
Short-term Debt	$ 23,678	$ 23,422
Securities Sold under Agreements to Repurchase
Short-term Debt [Line Items]
Short-term Debt	2,122	2,128
FHLB Advances
Short-term Debt [Line Items]
Short-term Debt	18,900	18,900
Dealer Collateral
Short-term Debt [Line Items]
Short-term Debt	455	403
Master Notes
Short-term Debt [Line Items]
Short-term Debt	310	370
Securities sold short
Short-term Debt [Line Items]
Short-term Debt	1,789	1,551
Other Short-term Borrowings
Short-term Debt [Line Items]
Short-term Debt	$ 102	$ 70