Fair Values of Assets and Liabilities - Fair Value Measurements, Recurring and Nonrecurring (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Financial Assets:
Cash and due from banks	$ 16,517	$ 6,069
Federal Home Loan Bank stock	2,498	2,986
Bank-owned life insurance	4,749	4,663
Loans, net	434,546	426,641
Accrued interest receivable	2,351	2,294
Financial Liabilities:
Deposits	447,686	404,798
Advances from Federal Home Loan Bank	52,268	73,007
Advances from Federal Reserve Bank	20,000	20,000
Mortgagors’ tax escrow	1,996	640
Accrued interest payable	1,233	380
Cash and due from banks [Member]
Financial Assets:
Financial Assets, Fair Value Disclosure	16,517	6,069
Federal Home Loan Bank stock [Member]
Financial Assets:
Financial Assets, Fair Value Disclosure	2,498	2,986
Federal Reserve Bank Advances [Member]
Financial Liabilities:
Financial Liabilities Fair Value Disclosure	20,005	20,020
Bank-owned life insurance [Member]
Financial Assets:
Financial Assets, Fair Value Disclosure	4,749	4,663
Loans, net [Member]
Financial Assets:
Financial Assets, Fair Value Disclosure	397,800	376,772
Accrued interest receivable [member]
Financial Assets:
Financial Assets, Fair Value Disclosure	2,351	2,294
Deposits [Member]
Financial Liabilities:
Financial Liabilities Fair Value Disclosure	447,908	403,489
Federal Home Loan Bank Borrowings [Member]
Financial Liabilities:
Financial Liabilities Fair Value Disclosure	52,640	73,162
Mortgagors' tax escrow [Member]
Financial Liabilities:
Financial Liabilities Fair Value Disclosure	1,996	640
Accrued interest payable [member]
Financial Liabilities:
Financial Liabilities Fair Value Disclosure	1,233	380
Fair Value, Inputs, Level 1 [Member] | Cash and due from banks [Member]
Financial Assets:
Financial Assets, Fair Value Disclosure	16,517	6,069
Fair Value, Inputs, Level 1 [Member] | Accrued interest receivable [member]
Financial Assets:
Financial Assets, Fair Value Disclosure	2,351	2,294
Fair Value, Inputs, Level 1 [Member] | Deposits [Member]
Financial Liabilities:
Financial Liabilities Fair Value Disclosure	319,844	313,503
Fair Value, Inputs, Level 1 [Member] | Accrued interest payable [member]
Financial Liabilities:
Financial Liabilities Fair Value Disclosure	1,233	380
Fair Value, Inputs, Level 2 [Member] | Federal Home Loan Bank stock [Member]
Financial Assets:
Financial Assets, Fair Value Disclosure	2,498	2,986
Fair Value, Inputs, Level 2 [Member] | Federal Reserve Bank Advances [Member]
Financial Liabilities:
Advances from Federal Reserve Bank	20,005	20,020
Fair Value, Inputs, Level 2 [Member] | Bank-owned life insurance [Member]
Financial Assets:
Financial Assets, Fair Value Disclosure	4,749	4,663
Fair Value, Inputs, Level 2 [Member] | Deposits [Member]
Financial Liabilities:
Financial Liabilities Fair Value Disclosure	128,064	89,986
Fair Value, Inputs, Level 2 [Member] | Federal Home Loan Bank Borrowings [Member]
Financial Liabilities:
Financial Liabilities Fair Value Disclosure	52,640	73,162
Fair Value, Inputs, Level 2 [Member] | Mortgagors' tax escrow [Member]
Financial Liabilities:
Financial Liabilities Fair Value Disclosure	1,996	640
Fair Value, Inputs, Level 3 [Member] | Loans, net [Member]
Financial Assets:
Financial Assets, Fair Value Disclosure	$ 397,800	$ 376,772