Loans - Schedule of Aging of Past Due and Nonaccrual Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 634,224	$ 545,487
Non-accrual	4,357	4,298
Total past due and non-accrual	4,636	5,646
Total ending loans balance	638,860	551,133
30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	240	830
60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	14	277
90 Days Plus Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	25	241
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	213,726	135,707
Non-accrual	1,381	1,325
Total past due and non-accrual	1,413	1,407
Total ending loans balance	215,139	137,114
Commercial [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	4	15
Commercial [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	3
Commercial [Member] | 90 Days Plus Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	25	67
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	196,634	194,157
Non-accrual	2,303	2,405
Total past due and non-accrual	2,314	2,591
Total ending loans balance	198,948	196,748
Commercial Real Estate [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	11	186
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	176,946	173,023
Non-accrual	641	521
Total past due and non-accrual	853	1,236
Total ending loans balance	177,799	174,259
Residential Real Estate [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	202	264
Residential Real Estate [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	10	277
Residential Real Estate [Member] | 90 Days Plus Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due		174
Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	28,123	23,960
Total ending loans balance	28,123	23,960
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	18,795	18,640
Non-accrual	32	47
Total past due and non-accrual	56	412
Total ending loans balance	18,851	19,052
Consumer [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	23	$ 365
Consumer [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Accruing Loans Total Past Due	$ 1