ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Accumulated Other Comprehensive income (loss) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Accumulated other comprehensive income (loss), net of tax:
Balance	$ 1,239,371	$ 1,226,225	$ 1,191,253	$ 1,169,583	$ 1,226,225	$ 1,169,583
Total other comprehensive income (loss), net of tax	2,686	6,113	(5,747)	(4,259)	8,799	(10,006)
Balance	1,250,596	1,239,371	1,202,503	1,191,253	1,250,596	1,202,503
AOCI Attributable to Parent [Member]
Accumulated other comprehensive income (loss), net of tax:
Balance	(85,466)	(91,579)	(98,638)	(94,379)	(91,579)	(94,379)
Other comprehensive income (loss) before reclassifications					4,805	(11,586)
Amounts reclassified from accumulated other comprehensive income (loss)					3,994	1,580
Total other comprehensive income (loss), net of tax	2,686	6,113	(5,747)	(4,259)	8,799	(10,006)
Balance	(82,780)	(85,466)	(104,385)	(98,638)	(82,780)	(104,385)
Securities
Accumulated other comprehensive income (loss), net of tax:
Balance		(90,242)		(100,870)	(90,242)	(100,870)
Other comprehensive income (loss) before reclassifications					4,761	(12,259)
Amounts reclassified from accumulated other comprehensive income (loss)					1,048	2,111
Total other comprehensive income (loss), net of tax					5,809	(10,148)
Balance	(84,433)		(111,018)		(84,433)	(111,018)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated other comprehensive income (loss), net of tax:
Balance		(6,430)		(5,266)	(6,430)	(5,266)
Other comprehensive income (loss) before reclassifications					703	729
Amounts reclassified from accumulated other comprehensive income (loss)					(433)	(521)
Total other comprehensive income (loss), net of tax					270	208
Balance	(6,160)		(5,058)		(6,160)	(5,058)
Derivatives
Accumulated other comprehensive income (loss), net of tax:
Balance		$ 5,093		$ 11,757	5,093	11,757
Other comprehensive income (loss) before reclassifications					(659)	(56)
Amounts reclassified from accumulated other comprehensive income (loss)					3,379	(10)
Total other comprehensive income (loss), net of tax					2,720	(66)
Balance	$ 7,813		$ 11,691		$ 7,813	$ 11,691