ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Summary of Changes in Accumulated Other Comprehensive Income or Loss by Component (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Changes in accumulated other comprehensive income or loss by component, net of tax [Roll Forward]
Beginning balance	$ 177,426	$ 174,690	$ 166,388	$ 211,455
Other comprehensive income before reclassification	(13,941)	(24,547)	(13,448)	(73,381)
Amounts reclassified from accumulated other comprehensive income	8	11	26	30
Total other comprehensive loss	(13,933)	(24,536)	(13,422)	(73,351)
Ending balance	170,064	155,518	170,064	155,518
Total
Changes in accumulated other comprehensive income or loss by component, net of tax [Roll Forward]
Beginning balance	(74,746)	(55,345)	(75,257)	(6,530)
Total other comprehensive loss	(13,933)	(24,536)	(13,422)	(73,351)
Ending balance	(88,679)	(79,881)	(88,679)	(79,881)
Unrealized Gains and Losses on Securities Available for Sale
Changes in accumulated other comprehensive income or loss by component, net of tax [Roll Forward]
Beginning balance	(70,803)	(51,329)	(71,296)	(2,495)
Other comprehensive income before reclassification	(13,941)	(24,547)	(13,448)	(73,381)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Total other comprehensive loss	(13,941)	(24,547)	(13,448)	(73,381)
Ending balance	(84,744)	(75,876)	(84,744)	(75,876)
Defined Benefit and Other Benefit Plans
Changes in accumulated other comprehensive income or loss by component, net of tax [Roll Forward]
Beginning balance	(3,943)	(4,016)	(3,961)	(4,035)
Other comprehensive income before reclassification	0	0	0	0
Amounts reclassified from accumulated other comprehensive income	8	11	26	30
Total other comprehensive loss	8	11	26	30
Ending balance	$ (3,935)	$ (4,005)	$ (3,935)	$ (4,005)