Income Taxes - Reconciliation of Tax Expense at the Federal Statutory Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Tax expense at the federal statutory tax rate	$ 56,689	$ 49,861	$ 43,764
Increase (decrease) in tax expense from:
Tax-exempt income, net	(343)	(337)	(436)
Modified endowment life contracts	(497)	(487)	(501)
Share based compensation excess tax benefit	(786)	(2,905)	(1,643)
Tax deductible dividends paid on ESOP	(505)	(481)	(490)
State tax expense, net of federal tax benefit	4,945	3,788	4,779
Bargain purchase gain			(1,007)
Utilization of tax credits:
New markets tax credits, net of amortization	(777)	(3,745)	(3,192)
Low-income housing tax credits, net of amortization	(1,106)	(1,024)	(1,533)
Other tax credits, net of amortization	(192)	(91)	(379)
Other, net	55	(247)	1,406
Total income taxes	$ 57,483	$ 44,332	$ 40,768