Loans and Allowance For Loan Losses - Summary of Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 11,565	$ 11,250	$ 11,075	$ 10,800
Provision for loan losses	2,930	246	3,330	826
Charge offs	(1,976)		(1,976)	(137)
Recoveries	5	5	95	12
Ending balance	12,524	11,501	12,524	11,501
Commercial And Industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	7,843	5,826	6,708	5,401
Provision for loan losses	1,871	1,823	2,916	2,241
Charge offs	(1,868)		(1,868)
Recoveries	5	5	95	12
Ending balance	7,851	7,654	7,851	7,654
Real Estate, Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	2,661	4,099	3,281	3,677
Provision for loan losses	671	(1,411)	51	(989)
Ending balance	3,332	2,688	3,332	2,688
Real Estate Construction And Land [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	730	1,120	1,022	1,524
Provision for loan losses	226	(175)	(66)	(579)
Ending balance	956	945	956	945
SBA [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	321	188	50	172
Provision for loan losses	153	11	424	164
Charge offs	(108)		(108)	(137)
Ending balance	366	199	366	199
Other Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	10	17	14	26
Provision for loan losses	9	(2)	5	(12)
Ending balance	$ 19	$ 15	$ 19	$ 15