Borrowings - Additional Information (Details) - USD ($)	Jun. 30, 2022	Dec. 31, 2021
Debt Disclosure
FHLB advances maximum amount available	$ 3,000,000,000.0	$ 3,000,000,000.0
Federal Home Loan Bank Advances And Letters Of Credit Amount Used	400,000,000	600,000,000
Assets sold under agreements to repurchase	70,925,000	91,603,000
Other short-term borrowings	0	75,000,000
Advances with FRB
Debt Disclosure
Line Of Credit Facility Current Borrowing Capacity	1,400,000,000	1,300,000,000
Federal Home Loan Bank
Debt Disclosure
Line Of Credit Facility Capacity Available For Specific Purpose Other Than For Trade Purchases	500,000,000	1,200,000,000
Other short-term borrowings	$ 0	$ 75,000,000