ALLOWANCE FOR CREDIT LOSSES - Summary of allowance for credit lost by portfolio segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 13,027	$ 14,413	$ 14,154	$ 13,400
Charge-offs	(12)	(29)	(45)	(47)
Recoveries	2	2	10	3
Recovery of credit loss on loans	(5)	(514)	(1,107)	(152)
Balance at end of period	13,012	13,872	13,012	13,872
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	0	0	0	668
Residential Portfolio Segment | Residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	1,825	1,994	1,968	2,264
Charge-offs	0	(18)	0	(18)
Recoveries	0	0	0	0
Recovery of credit loss on loans	17	(10)	(126)	(97)
Balance at end of period	1,842	1,966	1,842	1,966
Residential Portfolio Segment | Residential | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period				(183)
Residential Portfolio Segment | Multifamily
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	6,677	7,017	7,046	5,491
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Recovery of credit loss on loans	(84)	(194)	(453)	(725)
Balance at end of period	6,593	6,823	6,593	6,823
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
Commercial Real Estate Portfolio Segment | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	3,696	3,813	3,748	3,357
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Recovery of credit loss on loans	(36)	(85)	(88)	225
Balance at end of period	3,660	3,728	3,660	3,728
Commercial Real Estate Portfolio Segment | Commercial real estate | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period				146
Construction and Land Portfolio Segment | Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	636	1,428	1,222	1,697
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Recovery of credit loss on loans	14	(261)	(572)	302
Balance at end of period	650	1,167	650	1,167
Construction and Land Portfolio Segment | Construction | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period				(832)
Junior Lien Portfolio Segment | Junior liens
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	84	50	76	451
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Recovery of credit loss on loans	4	4	12	8
Balance at end of period	88	54	88	54
Junior Lien Portfolio Segment | Junior liens | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period				(405)
Commercial Portfolio Segment | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	108	111	94	47
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Recovery of credit loss on loans	45	23	59	110
Balance at end of period	153	134	153	134
Commercial Portfolio Segment | Commercial and industrial | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period				(23)
Consumer and Other Portfolio Segment | Consumer and other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	1	0	0	0
Charge-offs	(12)	(11)	(45)	(29)
Recoveries	2	2	10	3
Recovery of credit loss on loans	35	9	61	25
Balance at end of period	$ 26	0	$ 26	0
Consumer and Other Portfolio Segment | Consumer and other | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period				1
Unallocated Financing Receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period				93
Charge-offs				0
Recoveries				0
Recovery of credit loss on loans				0
Balance at end of period		$ 0		0
Unallocated Financing Receivables | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period				$ (93)