Borrowings - Short-term Borrowings (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Short-term Debt [Line Items]
Short-term Debt	$ 24,456	$ 23,422
Securities Sold under Agreements to Repurchase
Short-term Debt [Line Items]
Short-term Debt	3,165	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	463	403
Master Notes
Short-term Debt [Line Items]
Short-term Debt	242	370
Securities sold short
Short-term Debt [Line Items]
Short-term Debt	1,585	1,551
Other Short-term Borrowings
Short-term Debt [Line Items]
Short-term Debt	$ 101	$ 70