OTHER COMPREHENSIVE INCOME (LOSS) Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 495,064	$ 451,278
Other comprehensive (loss) income before reclassifications	(2,681)	5,319
Less: Amounts reclassified from AOCI	(1,218)	(1,165)
Other comprehensive (loss) income	(1,463)	6,484
Ending Balance	501,577	464,874
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(101,552)	(125,955)
Ending Balance	(103,015)	(119,471)
Net Unrealized Gains (Losses) on Debt Securities(1)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(107,409)	(131,539)
Other comprehensive (loss) income before reclassifications	(5,148)	7,760
Less: Amounts reclassified from AOCI	(1,200)	(1,334)
Other comprehensive (loss) income	(3,948)	9,094
Ending Balance	(111,357)	(122,445)
Net Unrealized (Losses) Gains on Cash Flow Hedges(1)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	6,096	5,891
Other comprehensive (loss) income before reclassifications	2,467	(2,441)
Less: Amounts reclassified from AOCI	(24)	164
Other comprehensive (loss) income	2,491	(2,605)
Ending Balance	8,587	3,286
Defined Benefit Postretirement Plans(1)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(239)	(307)
Other comprehensive (loss) income before reclassifications	0	0
Less: Amounts reclassified from AOCI	6	5
Other comprehensive (loss) income	(6)	(5)
Ending Balance	$ (245)	$ (312)