Loans - Summary of Collateral Dependent Loans and Related ACL (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 5,710	$ 6,666
Commercial Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans	3,687	4,457
Commercial Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans	901	1,323
Residential Real Estate First Mortgages [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,034	855
Consumer Home Equity and Lines of Credit [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 88	$ 31