Condensed Financial Information - Parent Company Only - Condensed Statements of Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income
Other income (loss)	$ 268	$ 735	$ 1,234
Expense
Noninterest expenses	140,757	132,798	126,756
Income taxes benefit	32,294	17,259	23,272
Net Income	95,041	57,518	70,672
Parent Company
Income
Dividends from subsidiaries	50,648	29,961	36,905
Other income (loss)	34	(486)	408
Total Income	50,682	29,475	37,313
Expense
Interest on subordinated debentures	5,419	5,968	5,983
Noninterest expenses	1,498	549	464
Total Expense	6,917	6,517	6,447
Income before benefit for income taxes	43,765	22,958	30,866
Income taxes benefit	(1,445)	(1,645)	(1,646)
Income before equity in undistributed income of subsidiaries	45,210	24,603	32,512
Equity in undistributed income of subsidiaries	49,831	32,915	38,160
Net Income	$ 95,041	$ 57,518	$ 70,672