Loans - Schedule of Analysis of Past due Loans (Detail) - USD ($) $ in Thousands		Sep. 30, 2023	Dec. 31, 2022
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		$ 385,410	$ 359,876
Loans, gross	[1]	385,465	361,947
Commercial Real Estate [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		221,653	209,126
Loans, gross		221,653	210,858
Commercial Land Development [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	0
Loans, gross		0	0
Commercial Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		45,682	43,708
Loans, gross		45,682	43,708
Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		95,306	85,200
Loans, gross		95,361	85,444
Residential Real Estate Construction [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		2,707	3,248
Loans, gross		2,707	3,248
Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		19,897	18,497
Loans, gross		19,897	18,590
Consumer Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		165	97
Loans, gross		165	99
Loans Past Due 30-89 Days [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	1,987
Loans Past Due 30-89 Days [Member] | Commercial Real Estate [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	1,732
Loans Past Due 30-89 Days [Member] | Commercial Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	0
Loans Past Due 30-89 Days [Member] | Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	181
Loans Past Due 30-89 Days [Member] | Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	72
Loans Past Due 30-89 Days [Member] | Consumer Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	2
Loans Past Due 90+ Days [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		55	84
Loans Past Due 90+ Days [Member] | Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		55	63
Loans Past Due 90+ Days [Member] | Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	21
Total Past Due [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		55	2,071
Total Past Due [Member] | Commercial Real Estate [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	1,732
Total Past Due [Member] | Commercial Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	0
Total Past Due [Member] | Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		55	244
Total Past Due [Member] | Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		0	93
Total Past Due [Member] | Consumer Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans		$ 0	$ 2

[1] Totals do not include accrued interest receivable, which was $987,000 and $874,000 at September 30, 2023 and December 31, 2022, respectively, which is recorded separately on the Company’s Consolidated Balance Sheets.