Condensed Financial Information - Parent Company Only - Schedule of Condensed Income Statement (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statements of Income
Interest expense	$ 21,348,000	$ 29,584,000	$ 44,861,000
Income before income taxes	114,330,000	56,897,000	80,053,000
Income tax expense	22,529,000	9,981,000	14,334,000
Equity in undistributed income of subsidiaries:
Net income (loss)	91,801,000	46,916,000	65,719,000
Parent Company [Member]
Statements of Income
Dividends from Bank	57,526,000	9,746,000	29,681,000
Dividends from non-bank	0	0	0
Other income	23,009,000	21,803,000	23,943,000
Total operating income	80,535,000	31,549,000	53,624,000
Interest expense	7,149,000	6,762,000	5,043,000
Operating expenses	26,464,000	22,852,000	25,032,000
Income before income taxes	46,922,000	1,935,000	23,549,000
Income tax expense	(2,668,000)	(1,555,000)	(1,360,000)
Income before equity in undistributed income of subsidiaries	49,590,000	3,490,000	24,909,000
Equity in undistributed income of subsidiaries:
Bank	42,211,000	43,426,000	40,810,000
Non-banks	0	0	0
Net income (loss)	$ 91,801,000	$ 46,916,000	$ 65,719,000