ALLOWANCE FOR CREDIT LOSSES - Summary of allowance for credit lost by portfolio segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 13,400	$ 14,425
Charge-offs	(64)	(58)
Recoveries	4	34
Release of provision for credit losses / release of provision for loan losses	146	(1,001)
Balance at end of period	14,154	13,400
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	668	0
Balance at end of period		668
Residential Portfolio Segment | Residential one-to-four family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	2,264	2,822
Charge-offs	(18)	0
Recoveries	0	30
Release of provision for credit losses / release of provision for loan losses	(95)	(588)
Balance at end of period	1,968	2,264
Residential Portfolio Segment | Residential one-to-four family | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	(183)
Balance at end of period		(183)
Residential Portfolio Segment | Multifamily
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	5,491	5,263
Charge-offs	0	0
Recoveries	0	0
Release of provision for credit losses / release of provision for loan losses	(502)	228
Balance at end of period	7,046	5,491
Residential Portfolio Segment | Multifamily | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	2,057
Balance at end of period		2,057
Non-residential | Non-residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	3,357	2,846
Charge-offs	0	0
Recoveries	0	0
Release of provision for credit losses / release of provision for loan losses	245	511
Balance at end of period	3,748	3,357
Non-residential | Non-residential | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	146
Balance at end of period		146
Construction | Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	1,697	2,678
Charge-offs	0	0
Recoveries	0	0
Release of provision for credit losses / release of provision for loan losses	357	(981)
Balance at end of period	1,222	1,697
Construction | Construction | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	(832)
Balance at end of period		(832)
Commercial and industrial | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	47	51
Charge-offs	0	0
Recoveries	0	0
Release of provision for credit losses / release of provision for loan losses	70	(4)
Balance at end of period	94	47
Commercial and industrial | Commercial and industrial | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	(23)
Balance at end of period		(23)
Junior liens | Junior liens
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	451	636
Charge-offs	0	0
Recoveries	0	0
Release of provision for credit losses / release of provision for loan losses	30	(185)
Balance at end of period	76	451
Junior liens | Junior liens | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	(405)
Balance at end of period		(405)
Consumer and other | Consumer and other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	0	38
Charge-offs	(46)	(58)
Recoveries	4	4
Release of provision for credit losses / release of provision for loan losses	41	16
Balance at end of period	0	0
Consumer and other | Consumer and other | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	1
Balance at end of period		1
Unallocated
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	93	91
Charge-offs	0	0
Recoveries	0	0
Release of provision for credit losses / release of provision for loan losses	0	2
Balance at end of period	0	93
Unallocated | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ (93)
Balance at end of period		$ (93)