Loans Receivable and the Allowance for Loan Losses - Schedule of age analysis of past due loans (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Loans receivable	$ 1,023,622	$ 972,851
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans receivable	1,718
Past Due
Financing Receivable, Past Due [Line Items]
Loans receivable	1,718
Current
Financing Receivable, Past Due [Line Items]
Loans receivable	1,021,904	972,851
Residential real estate
Financing Receivable, Past Due [Line Items]
Loans receivable	113,119	120,358
Residential real estate | One-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable	5,758	7,189
Residential real estate | One-to-four family | Current
Financing Receivable, Past Due [Line Items]
Loans receivable	5,758	7,189
Residential real estate | Multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable	83,866	84,425
Residential real estate | Multi-family | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans receivable	949
Residential real estate | Multi-family | Past Due
Financing Receivable, Past Due [Line Items]
Loans receivable	949
Residential real estate | Multi-family | Current
Financing Receivable, Past Due [Line Items]
Loans receivable	82,917	84,425
Residential real estate | Mixed-use
Financing Receivable, Past Due [Line Items]
Loans receivable	23,495	28,744
Residential real estate | Mixed-use | Current
Financing Receivable, Past Due [Line Items]
Loans receivable	23,495	28,744
Non-residential real estate
Financing Receivable, Past Due [Line Items]
Loans receivable	26,633	50,016
Non-residential real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans receivable	769
Non-residential real estate | Past Due
Financing Receivable, Past Due [Line Items]
Loans receivable	769
Non-residential real estate | Current
Financing Receivable, Past Due [Line Items]
Loans receivable	25,864	50,016
Construction
Financing Receivable, Past Due [Line Items]
Loans receivable	780,858	683,830
Construction | Current
Financing Receivable, Past Due [Line Items]
Loans receivable	780,858	683,830
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans receivable	102,594	118,378
Commercial and industrial | Current
Financing Receivable, Past Due [Line Items]
Loans receivable	102,594	118,378
Consumer
Financing Receivable, Past Due [Line Items]
Loans receivable	418	269
Consumer | Current
Financing Receivable, Past Due [Line Items]
Loans receivable	$ 418	$ 269