Short-Term Borrowings (Summary of Short-Term Borrowings) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Short-term Debt [Line Items]
Year-end balance	$ 10,417	$ 903
Securities sold, not yet purchased	187	254
Total federal funds and other short-term borrowings	10,417	903
Federal Home Loan Bank advances
Short-term Debt [Line Items]
Average amount outstanding	$ 1,257	$ 0
Average rate	3.67%	0.00%
Highest month-end balance	$ 7,100	$ 0
Year-end balance	$ 7,100	$ 0
Average rate on outstanding advances at year-end	4.43%	0.00%
Total federal funds and other short-term borrowings	$ 7,100	$ 0
Federal funds purchased
Short-term Debt [Line Items]
Other short-term borrowings, year-end balances	232	421
Security repurchase agreements
Short-term Debt [Line Items]
Other short-term borrowings, year-end balances	$ 2,898	$ 228