Loans and Allowance For Loan Losses - Summary of Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 14,111	$ 11,075
Provision for loan losses	300	400
Recoveries	166	90
Ending balance	14,577	11,565
Commercial And Industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	8,923	6,708
Provision for loan losses	142	1,045
Recoveries	166	90
Ending balance	9,231	7,843
Real Estate, Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	3,877	3,281
Provision for loan losses	80	(620)
Ending balance	3,957	2,661
Real Estate Construction And Land [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	681	1,022
Provision for loan losses	117	(292)
Ending balance	798	730
SBA [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	604	50
Provision for loan losses	(29)	271
Ending balance	575	321
Other Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	26	14
Provision for loan losses	(10)	(4)
Ending balance	$ 16	$ 10