LOANS RECEIVABLE - Credit quality indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	$ 52,079	$ 92,329
Loan origination, year two	94,358	524,566
Loan origination, year three	525,515	304,995
Loan origination, year four	288,156	65,175
Loan origination, year five	63,724	82,358
Loan origination, more than five years	527,121	491,285
Revolving Loans	30	22
Total	1,550,983	1,560,730
Residential Portfolio Segment \| Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	10,095	13,338
Loan origination, year two	12,976	98,007
Loan origination, year three	92,391	109,193
Loan origination, year four	103,338	14,315
Loan origination, year five	13,975	18,460
Loan origination, more than five years	283,979	297,616
Revolving Loans	0	0
Total	516,754	550,929
Residential Portfolio Segment \| Residential \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	10,095	13,338
Loan origination, year two	12,976	98,007
Loan origination, year three	92,391	109,193
Loan origination, year four	103,338	14,315
Loan origination, year five	13,975	18,460
Loan origination, more than five years	279,092	291,069
Revolving Loans	0	0
Total	511,867	544,382
Residential Portfolio Segment \| Residential \| Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	0	0
Loan origination, year two	0	0
Loan origination, year three	0	0
Loan origination, year four	0	0
Loan origination, year five	0	0
Loan origination, more than five years	647	663
Revolving Loans	0	0
Total	647	663
Residential Portfolio Segment \| Residential \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	0	0
Loan origination, year two	0	0
Loan origination, year three	0	0
Loan origination, year four	0	0
Loan origination, year five	0	0
Loan origination, more than five years	4,240	5,884
Revolving Loans	0	0
Total	4,240	5,884
Residential Portfolio Segment \| Multifamily
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	4,307	17,144
Loan origination, year two	16,989	281,906
Loan origination, year three	279,121	158,705
Loan origination, year four	150,019	35,407
Loan origination, year five	34,775	56,739
Loan origination, more than five years	181,093	132,663
Revolving Loans	0	0
Total	666,304	682,564
Residential Portfolio Segment \| Multifamily \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	4,307	17,144
Loan origination, year two	16,989	281,906
Loan origination, year three	279,121	158,705
Loan origination, year four	150,019	35,407
Loan origination, year five	34,775	56,739
Loan origination, more than five years	180,968	132,517
Revolving Loans	0	0
Total	666,179	682,418
Residential Portfolio Segment \| Multifamily \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	0	0
Loan origination, year two	0	0
Loan origination, year three	0	0
Loan origination, year four	0	0
Loan origination, year five	0	0
Loan origination, more than five years	125	146
Revolving Loans	0	0
Total	125	146
Commercial Real Estate Portfolio Segment \| Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	15,748	26,610
Loan origination, year two	26,630	118,247
Loan origination, year three	116,483	14,785
Loan origination, year four	14,564	15,080
Loan origination, year five	14,747	5,386
Loan origination, more than five years	53,539	52,397
Revolving Loans	0	0
Total	241,711	232,505
Commercial Real Estate Portfolio Segment \| Commercial real estate \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	15,748	26,610
Loan origination, year two	26,630	118,247
Loan origination, year three	116,483	14,785
Loan origination, year four	14,564	15,080
Loan origination, year five	14,747	5,386
Loan origination, more than five years	52,692	51,493
Revolving Loans	0	0
Total	240,864	231,601
Commercial Real Estate Portfolio Segment \| Commercial real estate \| Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	0	0
Loan origination, year two	0	0
Loan origination, year three	0	0
Loan origination, year four	0	0
Loan origination, year five	0	0
Loan origination, more than five years	847	904
Revolving Loans	0	0
Total	847	904
Construction and Land Portfolio Segment \| Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	4,198	22,798
Loan origination, year two	26,050	21,067
Loan origination, year three	32,343	16,549
Loan origination, year four	17,490	0
Loan origination, year five	0	0
Loan origination, more than five years	0	0
Revolving Loans	0	0
Total	80,081	60,414
Construction and Land Portfolio Segment \| Construction \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	4,198	22,798
Loan origination, year two	26,050	21,067
Loan origination, year three	32,343	16,549
Loan origination, year four	17,490	0
Loan origination, year five	0	0
Loan origination, more than five years	0	0
Revolving Loans	0	0
Total	80,081	60,414
Junior Lien Portfolio Segment \| Junior liens
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	4,101	5,359
Loan origination, year two	5,046	5,234
Loan origination, year three	5,080	1,232
Loan origination, year four	1,210	296
Loan origination, year five	227	1,773
Loan origination, more than five years	8,510	8,609
Revolving Loans	0	0
Total	24,174	22,503
Junior Lien Portfolio Segment \| Junior liens \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	4,101	5,359
Loan origination, year two	5,046	5,234
Loan origination, year three	5,080	1,232
Loan origination, year four	1,210	296
Loan origination, year five	227	1,773
Loan origination, more than five years	8,466	8,560
Revolving Loans	0	0
Total	24,130	22,454
Junior Lien Portfolio Segment \| Junior liens \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	0	0
Loan origination, year two	0	0
Loan origination, year three	0	0
Loan origination, year four	0	0
Loan origination, year five	0	0
Loan origination, more than five years	44	49
Revolving Loans	0	0
Total	44	49
Commercial Portfolio Segment \| Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	5,929	7,055
Loan origination, year two	6,667	105
Loan origination, year three	97	4,531
Loan origination, year four	1,535	77
Loan origination, year five	0	0
Loan origination, more than five years	0	0
Revolving Loans	0	0
Total	14,228	11,768
Commercial Portfolio Segment \| Commercial and industrial \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	5,929	7,055
Loan origination, year two	5,966	105
Loan origination, year three	97	4,492
Loan origination, year four	1,520	77
Loan origination, year five	0	0
Loan origination, more than five years	0	0
Revolving Loans	0	0
Total	13,512	11,729
Commercial Portfolio Segment \| Commercial and industrial \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	0	0
Loan origination, year two	701	0
Loan origination, year three	0	39
Loan origination, year four	15	0
Loan origination, year five	0	0
Loan origination, more than five years	0	0
Revolving Loans	0	0
Total	716	39
Consumer and Other Portfolio Segment \| Consumer and other
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	7,701	25
Loan origination, year two	0	0
Loan origination, year three	0	0
Loan origination, year four	0	0
Loan origination, year five	0	0
Loan origination, more than five years	0	0
Revolving Loans	30	22
Total	7,731	47
Consumer and Other Portfolio Segment \| Consumer and other \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loan origination, year one	7,701	25
Loan origination, year two	0	0
Loan origination, year three	0	0
Loan origination, year four	0	0
Loan origination, year five	0	0
Loan origination, more than five years	0	0
Revolving Loans	30	22
Total	$ 7,731	$ 47

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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