Loans and Allowance For Credit Losses - Summary of Allowance for Loan Losses (Detail) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 15,382,000	$ 17,005,000	$ 15,032,000	$ 17,005,000	$ 14,081,000
Adoption of new accounting standard				(1,840,000)
Provision for credit / loan losses	340,000		925,000	804,000	1,875,000
Charge-offs	0	(247,000)	0	(247,000)	0
Recoveries	0		0	0	1,000
Ending balance	$ 15,722,000	15,382,000	$ 15,957,000	$ 15,722,000	$ 15,957,000
Alowance for credit losses / gross loans	0.99%		1.06%	0.99%	1.06%
Net recoveries (charge-offs) / gross loans	0.00%		0.00%	(0.02%)	0.00%
Commercial And Industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 10,719,000	10,620,000	$ 8,876,000	$ 10,620,000	$ 8,552,000
Adoption of new accounting standard				(1,566,000)
Provision for credit / loan losses	84,000		650,000	1,996,000	973,000
Charge-offs	0		0	(247,000)	0
Recoveries	0		0	0	1,000
Ending balance	$ 10,803,000	10,719,000	$ 9,526,000	$ 10,803,000	$ 9,526,000
Alowance for credit losses / gross loans	1.74%		1.62%	1.74%	1.62%
Net recoveries (charge-offs) / gross loans	0.00%		0.00%	(0.04%)	0.00%
Real Estate, Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 2,943,000	5,322,000	$ 5,080,000	$ 5,322,000	$ 4,524,000
Adoption of new accounting standard				(1,725,000)
Provision for credit / loan losses	27,000		163,000	(627,000)	719,000
Charge-offs	0		0	0	0
Recoveries	0		0	0	0
Ending balance	$ 2,970,000	2,943,000	$ 5,243,000	$ 2,970,000	$ 5,243,000
Alowance for credit losses / gross loans	0.35%		0.66%	0.35%	0.66%
Net recoveries (charge-offs) / gross loans	0.00%		0.00%	0.00%	0.00%
Real Estate Construction And Land [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 743,000	884,000	$ 783,000	$ 884,000	$ 681,000
Adoption of new accounting standard				1,000
Provision for credit / loan losses	(6,000)		124,000	(148,000)	226,000
Charge-offs	0		0	0	0
Recoveries	0		0	0	0
Ending balance	$ 737,000	743,000	$ 907,000	$ 737,000	$ 907,000
Alowance for credit losses / gross loans	1.22%		1.44%	1.22%	1.44%
Net recoveries (charge-offs) / gross loans	0.00%		0.00%	0.00%	0.00%
SBA [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 42,000	132,000	$ 283,000	$ 132,000	$ 309,000
Adoption of new accounting standard				(91,000)
Provision for credit / loan losses	(2,000)		(10,000)	(1,000)	(36,000)
Charge-offs	0		0	0	0
Recoveries	0		0	0	0
Ending balance	$ 40,000	42,000	$ 273,000	$ 40,000	$ 273,000
Alowance for credit losses / gross loans	0.81%		2.05%	0.81%	2.05%
Net recoveries (charge-offs) / gross loans	0.00%		0.00%	0.00%	0.00%
Other Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 935,000	47,000	$ 10,000	$ 47,000	$ 15,000
Adoption of new accounting standard				1,541,000
Provision for credit / loan losses	237,000		(2,000)	(416,000)	(7,000)
Charge-offs	0		0	0	0
Recoveries	0		0	0	0
Ending balance	$ 1,172,000	$ 935,000	$ 8,000	$ 1,172,000	$ 8,000
Alowance for credit losses / gross loans	2.97%		0.02%	2.97%	0.02%
Net recoveries (charge-offs) / gross loans	0.00%		0.00%	0.00%	0.00%