Loans - Additional Information (Detail) - USD ($)		9 Months Ended	12 Months Ended
		Sep. 30, 2023	Dec. 31, 2022
Loans and Leases Receivable Disclosure [Line Items]
Additional Loans Receivable	[1]	$ 385,465,000	$ 361,947,000
Loans modified as troubled debt restructurings			0
Overdrawn deposit account reclassified as loan		25,000	98,000
Loans 90 days or more past due and accruing interest		0	0
Nonaccrual Loans		701,000	769,000
Interest earned on nonaccrual loans		0
Troubled debt restructurings amount			538,000
Troubled debt restructurings nonaccrual amount			183,000
Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Additional Loans Receivable			0
Other Financial Institutions [Member]
Loans and Leases Receivable Disclosure [Line Items]
Participation loans transferred		29,800,000	30,300,000
Outstanding from loans purchased		39,400,000	$ 31,600,000
Available future draws		$ 57,500,000

[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.