ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Summary of Changes in Accumulated Other Comprehensive Income or Loss by Component (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Changes in accumulated other comprehensive income or loss by component, net of tax [Roll Forward]
Beginning balance	$ 177,342	$ 185,510	$ 166,388	$ 211,455
Other comprehensive income before reclassification	(5,282)	(17,747)	493	(48,834)
Amounts reclassified from accumulated other comprehensive income	9	7	18	19
Total other comprehensive income (loss)	(5,273)	(17,740)	511	(48,815)
Ending balance	177,426	174,690	177,426	174,690
Total
Changes in accumulated other comprehensive income or loss by component, net of tax [Roll Forward]
Beginning balance	(69,473)	(37,605)	(75,257)	(6,530)
Total other comprehensive income (loss)	(5,273)	(17,740)	511	(48,815)
Ending balance	(74,746)	(55,345)	(74,746)	(55,345)
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	(65,521)	(33,582)	(71,296)	(2,495)
Other comprehensive income before reclassification	(5,282)	(17,747)	493	(48,834)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Total other comprehensive income (loss)	(5,282)	(17,747)	493	(48,834)
Ending balance	(70,803)	(51,329)	(70,803)	(51,329)
Defined Benefit and Other Benefit Plans
Changes in accumulated other comprehensive income or loss by component, net of tax [Roll Forward]
Beginning balance	(3,952)	(4,023)	(3,961)	(4,035)
Other comprehensive income before reclassification	0	0	0	0
Amounts reclassified from accumulated other comprehensive income	9	7	18	19
Total other comprehensive income (loss)	9	7	18	19
Ending balance	$ (3,943)	$ (4,016)	$ (3,943)	$ (4,016)