ACCUMULATED OTHER COMPREHENSIVE INCOME - Changes in accumulated other comprehensive income by component, net of tax (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023		Sep. 30, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 366,534	$ 412,293	$ 393,718		$ 429,471
Other comprehensive income (loss) before reclassification	(2,491)	(8,674)	1,457		(27,603)
Amounts reclassified from accumulated other comprehensive income	(1,536)	(133)	(3,890)		421
Total other comprehensive income (loss), after tax	(4,027)	(8,807)	(2,433)		(27,182)
Balance at end of period	359,149	397,338	359,149		397,338
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(23,125)	(18,747)	(24,719)		(372)
Balance at end of period	(27,152)	(27,554)	(27,152)		(27,554)
Unrealized gain on cash flow hedge:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	12,450	7,673	11,091		(246)
Other comprehensive income (loss) before reclassification	3,435	4,294	7,144		11,745
Amounts reclassified from accumulated other comprehensive income	(1,535)	(198)	(3,885)		270
Total other comprehensive income (loss), after tax	1,900	4,096	3,259		12,015
Balance at end of period	14,350	11,769	14,350		11,769
Unrealized Gains and (Losses) on Available-for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(35,944)	(25,467)	(36,183)		1,091
Other comprehensive income (loss) before reclassification	(5,926)	(12,968)	(5,687)		(39,512)
Amounts reclassified from accumulated other comprehensive income	0	0			(14)
Total other comprehensive income (loss), after tax	(5,926)	(12,968)	(5,687)		(39,526)
Balance at end of period	(41,870)	(38,435)	(41,870)		(38,435)
Post-Retirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	369	(953)	373		(1,217)
Other comprehensive income (loss) before reclassification	0	0	0	[1]	164	[1]
Amounts reclassified from accumulated other comprehensive income	(1)	65	(5)		165
Total other comprehensive income (loss), after tax	(1)	65	(5)		329
Balance at end of period	$ 368	$ (888)	$ 368		$ (888)

[1] Benefit arising from plan amendment approved in June 2022.