Non-interest Income and Expense - Components of Non Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Other Income and Expenses [Abstract]
Base salaries, net of deferred loan origination costs	$ 17,537	$ 17,277	$ 33,048	$ 34,900
Incentive compensation	4,322	2,395	7,902	5,496
Benefits and other compensation costs	5,222	7,383	11,461	13,931
Total salaries and benefits expense	27,081	27,055	52,411	54,327
Occupancy	3,700	3,398	7,426	7,273
Data processing and software	3,201	3,657	6,403	7,024
Equipment	1,207	1,350	2,724	2,862
Intangible amortization	1,431	1,431	2,862	2,862
Advertising	734	531	1,114	1,196
ATM and POS network charges	1,551	1,210	2,797	2,583
Professional fees	1,046	741	1,640	1,444
Telecommunications	564	639	1,145	1,364
Regulatory assessments and insurance	618	360	1,230	455
Postage	124	283	322	573
Operational losses	212	184	421	405
Courier service	288	337	582	668
Gain on sale or acquisition of foreclosed assets	(15)	(16)	(66)	(57)
(Gain) loss on disposal of fixed assets	(426)	15	(426)	15
Other miscellaneous expense	2,855	4,375	5,204	7,306
Total other non-interest expense	17,090	18,495	33,378	35,973
Total non-interest expense	$ 44,171	$ 45,550	$ 85,789	$ 90,300