Loans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Loans and Leases Receivable Disclosure [Line Items]
Additional Loans Receivable	$ 397,714,000	$ 361,947,000
Loans modified as troubled debt restructurings		0
Overdrawn deposit account reclassified as loan	78,000	98,000
Loans 90 or more days past due and accruing interest	0	0
Nonaccrual Loans	1,110,000	769,000
Interest earned on nonaccrual loans	0
Accrued interest reversed	11,000
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	29,000,000	30,300,000
Outstanding from loans purchased	34,800,000	$ 31,600,000
Available future draws	$ 30,700,000