Short-Term Borrowings - Summary of Short-Term Borrowings and Weighted-Average Rates (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Short-term Debt [Line Items]
Federal funds purchased	$ 180	$ 281
Other short-term borrowings	4,838	980
Federal Funds Purchased
Short-term Debt [Line Items]
Short-term borrowings, average	381	333
Short-term borrowings, maximum month-end balance	$ 1,312	$ 365
Short-term borrowings, rate	4.22%	0.13%
Short-term borrowings, average rate	1.69%	0.12%
Other Short Term Borrowings
Short-term Debt [Line Items]
Short-term borrowings, average	$ 4,544	$ 1,107
Short-term borrowings, maximum month-end balance	$ 8,606	$ 1,353
Short-term borrowings, rate	3.75%	0.04%
Short-term borrowings, average rate	2.39%	0.15%