Loans Receivable and Related Allowance for Loan Losses - Loans accruing and nonaccrual loans (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Current	$ 745,208	$ 712,492
Non-Accrual	3,606	2,716
Total loans before allowance for loan losses	749,147	717,847
30-59 Days Past Due
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Past Due	69	2,256
60-89 Days Past Due
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Past Due	264	383
Real Estate Loans \| One-to-four-family Residential and Construction
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Current	210,243	230,952
Non-Accrual	2,080	2,067
Total loans before allowance for loan losses	212,447	234,421
Real Estate Loans \| One-to-four-family Residential and Construction \| 30-59 Days Past Due
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Past Due	10	1,021
Real Estate Loans \| One-to-four-family Residential and Construction \| 60-89 Days Past Due
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Past Due	114	381
Real Estate Loans \| Commercial Real Estate and Construction
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Current	342,129	322,922
Non-Accrual	1,231	311
Total loans before allowance for loan losses	343,485	323,843
Real Estate Loans \| Commercial Real Estate and Construction \| 30-59 Days Past Due
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Past Due		610
Real Estate Loans \| Commercial Real Estate and Construction \| 60-89 Days Past Due
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Past Due	125
Real Estate Loans \| Home Equity Loans and Lines of Credit
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Current	103,398	110,634
Non-Accrual	219	272
Total loans before allowance for loan losses	103,699	111,499
Real Estate Loans \| Home Equity Loans and Lines of Credit \| 30-59 Days Past Due
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Past Due	59	591
Real Estate Loans \| Home Equity Loans and Lines of Credit \| 60-89 Days Past Due
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Past Due	23	2
Commercial Business
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Current	88,901	47,420
Non-Accrual	74	60
Total loans before allowance for loan losses	88,975	47,514
Commercial Business \| 30-59 Days Past Due
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Past Due		34
Other Loans
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Current	537	564
Non-Accrual	2	6
Total loans before allowance for loan losses	541	$ 570
Other Loans \| 60-89 Days Past Due
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans
Past Due	$ 2

Amount of financing receivable not past due.

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Amount of financing receivable on nonaccrual status.

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Amount of financing receivable past due.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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