Non-interest Income and Expense - Components of Noninterest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other Income and Expenses [Abstract]
Base salaries, net of deferred loan origination costs									$ 84,861	$ 69,844	$ 70,164
Incentive compensation									17,908	14,957	10,022
Benefits and other compensation costs									27,083	21,550	31,935
Total salaries and benefits expense									129,852	106,351	112,121
Occupancy									15,493	14,910	14,528
Data processing and software									14,660	13,985	13,504
Equipment									5,733	5,358	5,704
ATM and POS network charges									6,984	6,040	5,433
Merger and acquisition expense									6,253	1,523	0
Advertising									3,694	2,899	2,827
Professional fees									4,392	3,657	3,222
Intangible amortization									6,334	5,464	5,724
Telecommunications									2,298	2,253	2,601
Regulatory assessments and insurance									3,142	2,581	1,594
Courier service									2,013	1,214	1,414
Operational losses									1,000	964	1,168
Postage									1,147	710	1,068
Gain on sale or acquisition of foreclosed assets									(481)	(233)	(235)
(Gain) loss on disposal of fixed assets									(1,070)	(439)	67
Other miscellaneous expense									15,201	11,038	12,018
Total other noninterest expense									86,793	71,924	70,637
Total noninterest expense	$ 59,469	$ 54,465	$ 56,264	$ 46,447	$ 46,679	$ 45,807	$ 44,171	$ 41,618	$ 216,645	$ 178,275	$ 182,758