INVESTMENT SECURITIES - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Allowance for credit losses:
Beginning balance	$ 721	$ 0
Recovery of credit losses	(11)	45
Charge-offs	0	(26)
Recoveries	0	0
Ending Balance	710	687
Adoption of ASU No. 2016-13
Allowance for credit losses:
Beginning balance		668
Non-GSE commercial certificates
Allowance for credit losses:
Beginning balance	54	0
Recovery of credit losses	(1)	(1)
Charge-offs	0	(26)
Recoveries	0	0
Ending Balance	53	58
Non-GSE commercial certificates \| Adoption of ASU No. 2016-13
Allowance for credit losses:
Beginning balance		85
Commercial PACE
Allowance for credit losses:
Beginning balance	258	0
Recovery of credit losses	(2)	7
Charge-offs	0	0
Recoveries	0	0
Ending Balance	256	262
Commercial PACE \| Adoption of ASU No. 2016-13
Allowance for credit losses:
Beginning balance		255
Residential PACE
Allowance for credit losses:
Beginning balance	409	0
Recovery of credit losses	(8)	39
Charge-offs	0	0
Recoveries	0	0
Ending Balance	$ 401	367
Residential PACE \| Adoption of ASU No. 2016-13
Allowance for credit losses:
Beginning balance		$ 328

Amount, excluding accrued interest, of allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479344/326-20-45-1

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- Definition

Amount, excluding accrued interest, of increase in allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity) from recovery.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

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- Definition

Amount, excluding accrued interest, of decrease in allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity) from writeoff.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

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- Definition

Amount, excluding accrued interest, of credit loss expense (reversal of expense) on investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

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