Commitments and Letters of Credit - Notional Amount of Commitments and Letter of Credit Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Commitments Net	$ 83	$ 76	$ 71
Commitments to extend credit
Loss Contingencies [Line Items]
Financial instrument of credit risk	2,356,539	2,353,991
Financial standby letters of credit
Loss Contingencies [Line Items]
Financial instrument of credit risk	18,417	18,824
Performance standby letters of credit
Loss Contingencies [Line Items]
Financial instrument of credit risk	12,853	10,663
Commercial letters of credit
Loss Contingencies [Line Items]
Financial instrument of credit risk	$ 573	$ 975