OTHER COMPREHENSIVE INCOME (LOSS) Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 451,278	$ 541,294
Other comprehensive income (loss) before reclassifications	5,319	(69,958)
Less: Amounts reclassified from AOCI	(1,165)	(274)
Other comprehensive income (loss)	6,484	(69,684)
Ending Balance	464,874	482,446
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(125,955)	(6,229)
Ending Balance	(119,471)	(75,913)
Net Unrealized Gains (Losses) on Debt Securities(1)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(131,539)	(1,173)
Other comprehensive income (loss) before reclassifications	7,760	(72,811)
Less: Amounts reclassified from AOCI	(1,334)	0
Other comprehensive income (loss)	9,094	(72,811)
Ending Balance	(122,445)	(73,984)
Net Unrealized (Losses) Gains on Cash Flow Hedges(1)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	5,891	(1,779)
Other comprehensive income (loss) before reclassifications	(2,441)	2,853
Less: Amounts reclassified from AOCI	164	(92)
Other comprehensive income (loss)	(2,605)	2,945
Ending Balance	3,286	1,166
Defined Benefit Postretirement Plans(1)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(307)	(3,277)
Other comprehensive income (loss) before reclassifications	0	0
Less: Amounts reclassified from AOCI	5	(182)
Other comprehensive income (loss)	(5)	182
Ending Balance	$ (312)	$ (3,095)