Borrowings - Additional Information (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Debt Instrument
FHLB advances maximum amount available	$ 3,400,000,000	$ 3,300,000,000
Federal Home Loan Bank Advances And Letters Of Credit Amount Used	400,000,000	800,000,000
Assets sold under agreements to repurchase	123,499,000	148,609,000
Other short-term borrowings	0	365,000,000
Advances with FRB
Debt Instrument
Line Of Credit Facility Current Borrowing Capacity	1,500,000,000	1,400,000,000
Federal Home Loan Bank
Debt Instrument
Line Of Credit Facility Capacity Available For Specific Purpose Other Than For Trade Purchases	300,000,000	400,000,000
Other short-term borrowings	$ 0	$ 365,000,000