Commitments and Contingent Liabilities - Notional Amount of Outstanding Commitments (Detail) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Commitments to extend credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	$ 2,439,529	$ 2,254,445
Financial standby letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	14,705	13,791
Performance standby letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	28,525	29,265
Commercial letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	$ 569	$ 554