Loans Receivable and the Allowance for Loan Losses - Schedule of age analysis of past due loans (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Loans Receivable and the Allowance for Loan Losses
Loans receivable	$ 1,117,417	$ 972,851
60-89 Days Past Due
Loans Receivable and the Allowance for Loan Losses
Loans receivable	1,578
Past Due
Loans Receivable and the Allowance for Loan Losses
Loans receivable	1,578
Current
Loans Receivable and the Allowance for Loan Losses
Loans receivable	1,115,839	972,851
Residential real estate
Loans Receivable and the Allowance for Loan Losses
Loans receivable	116,941	120,358
Residential real estate | One-to-four family
Loans Receivable and the Allowance for Loan Losses
Loans receivable	5,706	7,189
Residential real estate | One-to-four family | Current
Loans Receivable and the Allowance for Loan Losses
Loans receivable	5,706	7,189
Residential real estate | Multi-family
Loans Receivable and the Allowance for Loan Losses
Loans receivable	88,418	84,425
Residential real estate | Multi-family | Current
Loans Receivable and the Allowance for Loan Losses
Loans receivable	88,418	84,425
Residential real estate | Mixed-use
Loans Receivable and the Allowance for Loan Losses
Loans receivable	22,817	28,744
Residential real estate | Mixed-use | Current
Loans Receivable and the Allowance for Loan Losses
Loans receivable	22,817	28,744
Non-residential real estate
Loans Receivable and the Allowance for Loan Losses
Loans receivable	25,587	50,016
Non-residential real estate | Current
Loans Receivable and the Allowance for Loan Losses
Loans receivable	25,587	50,016
Construction
Loans Receivable and the Allowance for Loan Losses
Loans receivable	862,450	683,830
Construction | 60-89 Days Past Due
Loans Receivable and the Allowance for Loan Losses
Loans receivable	1,578
Construction | Past Due
Loans Receivable and the Allowance for Loan Losses
Loans receivable	1,578
Construction | Current
Loans Receivable and the Allowance for Loan Losses
Loans receivable	860,872	683,830
Commercial and industrial
Loans Receivable and the Allowance for Loan Losses
Loans receivable	111,416	118,378
Commercial and industrial | Current
Loans Receivable and the Allowance for Loan Losses
Loans receivable	111,416	118,378
Consumer
Loans Receivable and the Allowance for Loan Losses
Loans receivable	1,023	269
Consumer | Current
Loans Receivable and the Allowance for Loan Losses
Loans receivable	$ 1,023	$ 269