Commitments and Contingent Liabilities - Notional Amount of Outstanding Commitments (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Commitments to extend credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	$ 2,286,257	$ 2,353,991
Financial standby letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	17,444	18,824
Performance standby letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	17,336	10,663
Commercial letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	$ 882	$ 975