COMMITMENTS AND CONTINGENCIES - Investment holdings schedule (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Summary of Investment Holdings [Line Items]
Amortization Method Qualified Affordable Housing Project Investments	$ 167,296		$ 167,296		$ 158,440
Qualified Affordable Housing Project Investments, Commitment	94,801		94,801		84,334
Amortization Method Qualified Affordable Housing Project Investments, Amortization	3,842	$ 3,155	7,273	$ 6,308
Affordable Housing Tax Credits and Other Tax Benefits, Amount	(3,569)	(2,968)	(7,241)	(6,058)
Low Income Housing Tax Credits
Summary of Investment Holdings [Line Items]
Amortization Method Qualified Affordable Housing Project Investments	124,454		124,454		126,537
Qualified Affordable Housing Project Investments, Commitment	69,848		69,848		70,690
Amortization Method Qualified Affordable Housing Project Investments, Amortization	3,738	3,051	7,065	6,100
Affordable Housing Tax Credits and Other Tax Benefits, Amount	(3,437)	(2,835)	(6,977)	(5,794)
Historic tax credit [Member]
Summary of Investment Holdings [Line Items]
Amortization Method Qualified Affordable Housing Project Investments	16,049		16,049		17,108
Qualified Affordable Housing Project Investments, Commitment	11,955		11,955		11,955
Amortization Method Qualified Affordable Housing Project Investments, Amortization	0	0	0	0
Affordable Housing Tax Credits and Other Tax Benefits, Amount	(80)	(80)	(159)	(159)
New Markets Tax Credit
Summary of Investment Holdings [Line Items]
Amortization Method Qualified Affordable Housing Project Investments	2,445		2,445		2,944
Qualified Affordable Housing Project Investments, Commitment	0		0		0
Amortization Method Qualified Affordable Housing Project Investments, Amortization	104	104	208	208
Affordable Housing Tax Credits and Other Tax Benefits, Amount	(52)	(53)	(105)	(105)
Renewable Energy Program
Summary of Investment Holdings [Line Items]
Amortization Method Qualified Affordable Housing Project Investments	24,348		24,348		11,851
Qualified Affordable Housing Project Investments, Commitment	12,998		12,998		$ 1,689
Amortization Method Qualified Affordable Housing Project Investments, Amortization	0	0	0	0
Affordable Housing Tax Credits and Other Tax Benefits, Amount	$ 0	$ 0	$ 0	$ 0