Loans - Schedule of Analysis of Past due Loans (Detail) - USD ($) $ in Thousands		Jun. 30, 2024	Dec. 31, 2023
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross	[1]	$ 401,856	$ 397,714
Commercial Real Estate [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		237,645	231,893
Commercial Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		46,078	47,898
Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		98,419	97,747
Residential Real Estate Construction [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		691	359
Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		18,943	19,683
Consumer Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		80	134
Loans Past Due 30-89 Days [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		190	378
Loans Past Due 30-89 Days [Member] | Commercial Real Estate [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	79
Loans Past Due 30-89 Days [Member] | Commercial Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		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]
Loans, gross		91	299
Loans Past Due 30-89 Days [Member] | Residential Real Estate Construction [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	0
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]
Loans, gross		99	0
Loans Past Due 30-89 Days [Member] | Consumer Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	0
Loans Past Due 90+ Days [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		115	395
Loans Past Due 90+ Days [Member] | Commercial Real Estate [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	343
Loans Past Due 90+ Days [Member] | Commercial Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	0
Loans Past Due 90+ Days [Member] | Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		59	52
Loans Past Due 90+ Days [Member] | Residential Real Estate Construction [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	0
Loans Past Due 90+ Days [Member] | Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		56	0
Loans Past Due 90+ Days [Member] | Consumer Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	0
Total Past Due [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		305	773
Total Past Due [Member] | Commercial Real Estate [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	422
Total Past Due [Member] | Commercial Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	0
Total Past Due [Member] | Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		150	351
Total Past Due [Member] | Residential Real Estate Construction [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	0
Total Past Due [Member] | Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		155	0
Total Past Due [Member] | Consumer Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		0	0
Current Loans [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		401,551	396,941
Current Loans [Member] | Commercial Real Estate [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		237,645	231,471
Current Loans [Member] | Commercial Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		46,078	47,898
Current Loans [Member] | Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		98,269	97,396
Current Loans [Member] | Residential Real Estate Construction [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		691	359
Current Loans [Member] | Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		18,788	19,683
Current Loans [Member] | Consumer Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Loans, gross		$ 80	$ 134

[1] Totals do not include accrued interest receivable, which was $1.1 million at both June 30, 2024 and December 31, 2023, and which is recorded separately on the Company’s Consolidated Balance Sheets.