Allowance for Loan Losses - Summary of Risk Grades of Portfolio by Class (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable Recorded Investment [Line Items]
Loans	$ 445,924	$ 420,779
Real Estate - Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	154,734	150,543
Other Real Estate Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	42,713	28,275
Real Estate 1 - 4 Family Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	8,927	8,424
Real Estate - Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	84,729	79,324
Home Equity [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	52,666	51,003
Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	5,393	5,496
Paycheck Protection Program [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	7,599	15,100
Commercial Loan [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	80,123	73,035
Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	9,040	9,579
Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	437,704	408,945
Pass [Member] | Real Estate - Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	151,465	145,084
Pass [Member] | Other Real Estate Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	42,405	27,966
Pass [Member] | Real Estate 1 - 4 Family Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	8,927	8,424
Pass [Member] | Real Estate - Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	82,640	76,430
Pass [Member] | Home Equity [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	52,487	50,672
Pass [Member] | Other Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	5,393	5,496
Pass [Member] | Paycheck Protection Program [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	7,599	15,100
Pass [Member] | Commercial Loan [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	77,787	70,235
Pass [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	9,001	9,538
Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	6,709	9,428
Watch [Member] | Real Estate - Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	2,983	4,387
Watch [Member] | Other Real Estate Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	54	55
Watch [Member] | Real Estate - Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	1,530	2,157
Watch [Member] | Home Equity [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	148	298
Watch [Member] | Commercial Loan [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	1,955	2,490
Watch [Member] | Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	39	41
Sub-standard [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	1,511	2,406
Sub-standard [Member] | Real Estate - Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	286	1,072
Sub-standard [Member] | Other Real Estate Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	254	254
Sub-standard [Member] | Real Estate - Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	559	737
Sub-standard [Member] | Home Equity [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	31	33
Sub-standard [Member] | Commercial Loan [Member]
Financing Receivable Recorded Investment [Line Items]
Loans	$ 381	$ 310