Allowance for loan Losses - Changes in the Allowance for Credit Losses (Parenthetical) (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Jan. 01, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reserve for credit losses	$ 38,849	$ 36,170			$ 28,511
ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reserve for credit losses				$ 37,861
PCD Loans [Member] | ASU 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reserve for credit losses			$ 1,668	$ 1,668
Loans and leases receivable allowance net of change in estimates			$ 771