Loans - Summary of Internal Risk Ratings of Loans (Detail) - USD ($) $ in Thousands		Sep. 30, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount	[1]	$ 385,465	$ 361,947
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount		221,653	210,858
Commercial Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount		0	0
Commercial Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount		$ 45,682	43,708
Internal Credit Risk Rating [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			254,566
Internal Credit Risk Rating [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			210,858
Internal Credit Risk Rating [Member] | Commercial Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			0
Internal Credit Risk Rating [Member] | Commercial Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			43,708
Pass [Member] | Internal Credit Risk Rating [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			248,224
Pass [Member] | Internal Credit Risk Rating [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			206,655
Pass [Member] | Internal Credit Risk Rating [Member] | Commercial Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			0
Pass [Member] | Internal Credit Risk Rating [Member] | Commercial Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			41,569
Watch and Special Mention [Member] | Internal Credit Risk Rating [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			2,967
Watch and Special Mention [Member] | Internal Credit Risk Rating [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			2,932
Watch and Special Mention [Member] | Internal Credit Risk Rating [Member] | Commercial Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			0
Watch and Special Mention [Member] | Internal Credit Risk Rating [Member] | Commercial Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			35
Substandard [Member] | Internal Credit Risk Rating [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			3,375
Substandard [Member] | Internal Credit Risk Rating [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			1,271
Substandard [Member] | Internal Credit Risk Rating [Member] | Commercial Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			0
Substandard [Member] | Internal Credit Risk Rating [Member] | Commercial Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivable gross carrying amount			$ 2,104

[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.