Loans Receivable and Allowance for Credit Losses - Aging of Loans and Accrual Status by Class (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment, Past Due
Total Loans	$ 1,308,552,000	$ 1,296,796,000
Nonaccrual Loans	2,260,000	2,301,000
One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,275,615,000	1,251,554,000
Nonaccrual Loans	2,079,000	2,279,000
Multi-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	5,848,000	6,439,000
Construction, Commercial and Other Mortgage Loans
Financing Receivable, Recorded Investment, Past Due
Total Loans	11,570,000	23,775,000
Home equity loans and lines of credit
Financing Receivable, Recorded Investment, Past Due
Total Loans	7,060,000	6,427,000
Nonaccrual Loans	11,000	16,000
Loans on Deposit Accounts
Financing Receivable, Recorded Investment, Past Due
Total Loans	196,000	217,000
Consumer and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	8,263,000	8,384,000
Nonaccrual Loans	170,000	6,000
Not Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,307,893,000	1,295,816,000
Not Past Due | One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,274,960,000	1,250,586,000
Not Past Due | Multi-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	5,848,000	6,439,000
Not Past Due | Construction, Commercial and Other Mortgage Loans
Financing Receivable, Recorded Investment, Past Due
Total Loans	11,570,000	23,775,000
Not Past Due | Home equity loans and lines of credit
Financing Receivable, Recorded Investment, Past Due
Total Loans	7,060,000	6,427,000
Not Past Due | Loans on Deposit Accounts
Financing Receivable, Recorded Investment, Past Due
Total Loans	196,000	217,000
Not Past Due | Consumer and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	8,259,000	8,372,000
Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	659,000	980,000
Past Due | One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	655,000	968,000
Past Due | Consumer and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	4,000	12,000
30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	432,000	6,000
30 - 59 Days Past Due | One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	428,000
30 - 59 Days Past Due | Consumer and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	4,000	6,000
60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans		409,000
60 - 89 Days Past Due | One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans		409,000
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	227,000	565,000
90 Days or More Past Due | One- to four-family residential
Financing Receivable, Recorded Investment, Past Due
Total Loans	$ 227,000	559,000
90 Days or More Past Due | Consumer and other
Financing Receivable, Recorded Investment, Past Due
Total Loans		$ 6,000