COMPREHENSIVE INCOME (LOSS) - Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
COMPREHENSIVE INCOME (LOSS)
Unrealized holding losses on available-for-sale debt securities	$ (69,828)	$ (8,669)	$ 10,504
Unrealized holding losses on available-for-sale debt securities, Income Tax Effect	14,665	1,821	(2,205)
Unrealized holding losses on available-for-sale debt securities, Net of Tax Amount	(55,163)	(6,848)	8,299
Reclassification adjustment for (gains) realized in income	(20)	(24)	(169)
Reclassification adjustment for (gains) losses realized in income, Income Tax Effect	4	5	35
Reclassification adjustment for (gains) losses realized in income. Net of Tax Amount	(16)	(19)	(134)
Other comprehensive loss from available-for-sale debt securities, Before-Tax Amount	(69,848)	(8,693)	10,335
Other comprehensive loss on available-for-sale debt securities, Income tax effect	14,669	1,826	(2,170)
Other comprehensive loss from available-for-sale debt securities, Net-of-Tax Amount	(55,179)	(6,867)	8,165
Changes from plan amendments and actuarial gains and losses, Before-Tax Amount	389	140	(49)
Changes from plan amendments and actuarial gains and losses, Income Tax Effect	(81)	(29)	11
Changes from plan amendments and actuarial gains and losses, Net-of-Tax Amount	308	111	(38)
Amortization of prior service cost and net actuarial loss included in net periodic benefit cost, Before-Tax Amount	(42)	(17)	(29)
Amortization of prior service cost and net actuarial loss included in net periodic benefit cost, Income Tax Effect	9	4	6
Amortization of prior service cost and net actuarial loss included in net periodic benefit cost, Net-of-Tax Amount	(33)	(13)	(23)
Other comprehensive income (loss) on pension and postretirement obligations	347	123	(78)
Other comprehensive income (loss) on unfunded retirement obligations, Income Tax Effect	(72)	(25)	17
Other comprehensive income (loss) on unfunded retirement obligations, Net-of-Tax Amount	275	98	(61)
Other comprehensive (loss) income before income tax	(69,501)	(8,570)	10,257
Total other comprehensive income (loss), Income Tax Effect	14,597	1,801	(2,153)
Total other comprehensive income (loss), Net-of-Tax Amount	$ (54,904)	$ (6,769)	$ 8,104