Income Taxes - Reconciliation Between Income Tax Expense and Amount Computed by Applying Federal Statutory Tax Rate from Continuing Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Statutory federal income tax expense	$ 90,103	$ 71,167	$ 60,053
Tax-exempt interest income	(20,635)	(20,914)	(18,725)
Tax-exempt life insurance related income	(2,631)	(3,420)	(4,007)
Meals, entertainment and related expenses	580	924	1,647
State and local income taxes, net of federal tax benefits	10,659	5,835	4,273
Equity-based compensation	(1,889)	(299)	(597)
Federal tax credits, net of amortization of LIHTC investments	(2,634)	(1,772)	(980)
Other	2,489	867	701
Total tax expense	$ 76,042	$ 52,388	$ 42,365