Commitments and Letters of Credit - Notional Amount of Commitments and Letter of Credit Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Commitments to extend credit
Loss Contingencies [Line Items]
Financial instrument of credit risk	$ 2,425,873	$ 2,254,445
Financial standby letters of credit
Loss Contingencies [Line Items]
Financial instrument of credit risk	14,371	13,791
Performance standby letters of credit
Loss Contingencies [Line Items]
Financial instrument of credit risk	16,620	29,265
Commercial letters of credit
Loss Contingencies [Line Items]
Financial instrument of credit risk	$ 569	$ 554