Commitments and Contingent Liabilities - Notional Amount of Outstanding Commitments (Detail) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Commitments to extend credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	$ 2,389,860	$ 2,425,873
Financial standby letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	14,227	14,371
Performance standby letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	15,058	16,620
Commercial letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	$ 569	$ 569

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details