Commitments and Contingencies - Additional Information (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Financial Instruments With Off Balance Sheet Credit Risk [Line Items]
Commitments to lend additional funds to borrowers	$ 39,000	$ 0
Maximum
Schedule Of Financial Instruments With Off Balance Sheet Credit Risk [Line Items]
Standby letters of credit	19,500,000	14,800,000
Commitments to Extend Credit
Schedule Of Financial Instruments With Off Balance Sheet Credit Risk [Line Items]
Financial instruments with off-balance sheet risks, contract amount	$ 1,140,000,000	$ 1,110,000,000