ACCUMULATED OTHER COMPREHENSIVE INCOME - Schedule of components of other comprehensive loss (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized loss arising during the period, before tax				$ 1,594	$ (18,427)
Unrealized loss arising during the period, tax effect				0	52
Unrealized loss arising during the period, after tax		$ 1,349	$ (8,427)	3,948	(18,929)
Total other comprehensive income (loss), before tax		1	(8,246)
Total other comprehensive income (loss), tax effect		0	3
Total other comprehensive income (loss), after tax		1	(8,243)	1,594	(18,375)
Unrealized loss on securities available-for-sale:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized loss arising during the period, before tax		(3,800)	(10,808)	239	(26,596)
Unrealized loss arising during the period, tax effect		0	3	0	52
Unrealized loss arising during the period, after tax		(3,800)	(10,805)	239	(26,544)
Reclassification adjustment for (gains) losses included in net income, before tax		0	(14)	0	(14)
Reclassification adjustment for (gains) losses included in net income, tax effect		0	0	0	0
Reclassification adjustment for (gains) losses included in net income, after tax		0	(14)	0	(14)
Total other comprehensive income (loss), before tax		(3,800)	(10,822)	239	(26,610)
Total other comprehensive income (loss), tax effect		0	3	0	52
Total other comprehensive income (loss), after tax		(3,800)	(10,819)	239	(26,558)
Unrealized gain on cash flow hedge:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized loss arising during the period, before tax		5,149	2,214	3,709	7,451
Unrealized loss arising during the period, tax effect		0	0	0	0
Unrealized loss arising during the period, after tax		5,149	2,214	3,709	7,451
Reclassification adjustment for (gains) losses included in net income, before tax		(1,346)	146	(2,350)	468
Reclassification adjustment for (gains) losses included in net income, tax effect		0	0	0	0
Reclassification adjustment for (gains) losses included in net income, after tax		(1,346)	146	(2,350)	468
Total other comprehensive income (loss), before tax		3,803	2,360	1,359	7,919
Total other comprehensive income (loss), tax effect		0	0	0	0
Total other comprehensive income (loss), after tax		3,803	2,360	1,359	7,919
Post-Retirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized loss arising during the period, before tax		0	164	0	164
Unrealized loss arising during the period, tax effect		0	0	0	0
Unrealized loss arising during the period, after tax	[1]	0	164	0	164
Reclassification adjustment for (gains) losses included in net income, before tax		(2)	52	(4)	100
Reclassification adjustment for (gains) losses included in net income, tax effect		0	0	0	0
Reclassification adjustment for (gains) losses included in net income, after tax		(2)	52	(4)	100
Total other comprehensive income (loss), before tax		(2)	216	(4)	264
Total other comprehensive income (loss), tax effect		0	0	0	0
Total other comprehensive income (loss), after tax		$ (2)	$ 216	$ (4)	$ 264

[1] Benefit arising from plan amendment approved in June 2022.