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, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Changes in accumulated other comprehensive income or loss by component, net of tax [Roll Forward]
Beginning balance	$ 185,510	$ 194,784	$ 211,455	$ 199,699
Other comprehensive income before reclassification	(17,747)	3,893	(48,834)	(6,260)
Amounts reclassified from accumulated other comprehensive income	7	1	19	1
Total other comprehensive income (loss)	(17,740)	3,894	(48,815)	(6,259)
Ending balance	174,690	203,977	174,690	203,977
Total
Changes in accumulated other comprehensive income or loss by component, net of tax [Roll Forward]
Beginning balance	(37,605)	(7,752)	(6,530)	2,401
Total other comprehensive income (loss)	(17,740)	3,894	(48,815)	(6,259)
Ending balance	(55,345)	(3,858)	(55,345)	(3,858)
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	(33,582)	(1,026)	(2,495)	9,127
Other comprehensive income before reclassification	(17,747)	3,893	(48,834)	(6,260)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Total other comprehensive income (loss)	(17,747)	3,893	(48,834)	(6,260)
Ending balance	(51,329)	2,867	(51,329)	2,867
Defined Benefit and Other Benefit Plans
Changes in accumulated other comprehensive income or loss by component, net of tax [Roll Forward]
Beginning balance	(4,023)	(6,726)	(4,035)	(6,726)
Other comprehensive income before reclassification	0	0	0	0
Amounts reclassified from accumulated other comprehensive income	7	1	19	1
Total other comprehensive income (loss)	7	1	19	1
Ending balance	$ (4,016)	$ (6,725)	$ (4,016)	$ (6,725)