Allowances for Loan Losses - Summary of Classes of the Loan Portfolio Summarized by the Internal Risk Rating System (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	$ 415,807	$ 328,247
Commercial and industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	129,835	101,370
Construction and land development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	25,177	20,935
Real estate - commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	193,488	145,800
Real estate - residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	41,891	37,302
Real estate - home equity [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	21,987	20,218
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	3,429	2,622
Pass [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	406,221	326,248
Pass [Member] | Commercial and industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	125,705	100,289
Pass [Member] | Construction and land development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	25,177	20,935
Pass [Member] | Real estate - commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	188,367	145,358
Pass [Member] | Real estate - residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	41,559	36,892
Pass [Member] | Real estate - home equity [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	21,987	20,155
Pass [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	3,426	2,619
Special Mention [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	7,855	354
Special Mention [Member] | Commercial and industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	3,180	0
Special Mention [Member] | Construction and land development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	0
Special Mention [Member] | Real estate - commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	4,568	212
Special Mention [Member] | Real estate - residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	107	142
Special Mention [Member] | Real estate - home equity [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	0
Special Mention [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	0
Substandard [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	1,731	1,645
Substandard [Member] | Commercial and industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	950	1,081
Substandard [Member] | Construction and land development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	0
Substandard [Member] | Real estate - commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	553	230
Substandard [Member] | Real estate - residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	225	268
Substandard [Member] | Real estate - home equity [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	63
Substandard [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	3	3
Doubtful [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	0
Doubtful [Member] | Commercial and industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	0
Doubtful [Member] | Construction and land development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	0
Doubtful [Member] | Real estate - commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	0
Doubtful [Member] | Real estate - residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	0
Doubtful [Member] | Real estate - home equity [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	0	0
Doubtful [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans receivable	$ 0	$ 0