Loans and Allowance For Loan Losses - Summary of Financing Receivable and Related Impairment Methodology (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Total gross loans	$ 1,470,313	$ 1,369,070
Commercial And Industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total gross loans	439,044	414,548
Real Estate Construction & Land [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total gross loans	45,550	37,193
SBA [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total gross loans	364,273	317,564
Other Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total gross loans	47,926	49,075
Loans Receivable [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans individually evaluated for impairment	2,560	2,977
Loans collectively evaluated for impairment	1,467,753	1,366,093
Total gross loans	1,470,313	1,369,070
Loans individually evaluated for impairment	299	300
Loans collectively evaluated for impairment	14,278	13,811
Total allowance for loan losses	14,577	14,111
Loans Receivable [Member] \| Commercial And Industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans individually evaluated for impairment	1,873	2,288
Loans collectively evaluated for impairment	437,171	412,260
Total gross loans	439,044	414,548
Loans individually evaluated for impairment	41	41
Loans collectively evaluated for impairment	9,190	8,882
Total allowance for loan losses	9,231	8,923
Loans Receivable [Member] \| Real Estate - Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans collectively evaluated for impairment	573,520	550,690
Total gross loans	573,520	550,690
Loans collectively evaluated for impairment	3,957	3,877
Total allowance for loan losses	3,957	3,877
Loans Receivable [Member] \| Real Estate Construction & Land [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans collectively evaluated for impairment	45,550	37,193
Total gross loans	45,550	37,193
Loans collectively evaluated for impairment	798	681
Total allowance for loan losses	798	681
Loans Receivable [Member] \| SBA [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans individually evaluated for impairment	687	689
Loans collectively evaluated for impairment	363,586	316,875
Total gross loans	364,273	317,564
Loans individually evaluated for impairment	258	259
Loans collectively evaluated for impairment	317	345
Total allowance for loan losses	575	604
Loans Receivable [Member] \| Other Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans collectively evaluated for impairment	47,926	49,075
Total gross loans	47,926	49,075
Loans collectively evaluated for impairment	16	26
Total allowance for loan losses	$ 16	$ 26

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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