COMPREHENSIVE INCOME - Components (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
COMPREHENSIVE INCOME
Unrealized holding gains (losses) on available-for-sale debt securities, Before-Tax Amount	$ (812)	$ (6,663)	$ (3,586)	$ 2,330
Unrealized holding (losses) gains on available-for-sale debt securities, Income Tax Effect	173	1,397	754	(491)
Unrealized holding (losses) gains on available-for-sale debt securities, Net of Tax Amount	(639)	(5,266)	(2,832)	1,839
Reclassification adjustment for (gains) losses realized in income, Before-Tax Amount	0	1	0	(6)
Reclassification adjustment for gains (losses) realized in income, Income Tax Effect	0	0	0	1
Reclassification adjustment for (gains) losses realized in income. Net of Tax Amount	0	1	0	(5)
Other comprehensive (loss) income from available-for-sale debt securities, Before-Tax Amount	(812)	(6,662)	(3,586)	2,324
Other comprehensive loss (income) from available-for-sale debt securities, Income tax effect	173	1,397	754	(490)
Other comprehensive (loss) income from available-for-sale debt securities, Net-of-Tax Amount	(639)	(5,265)	(2,832)	1,834
Changes from plan amendments and actuarial gains and losses, Before-Tax Amount	0	0	394	(8)
Changes from plan amendments and actuarial gains and losses, Income Tax Effect			(83)	1
Changes from plan amendments and actuarial gains and losses, Net-of-Tax Amount			311	(7)
Amortization of prior service cost and net actuarial loss and curtailment gain included in net periodic benefit cost, Before-Tax Amount	(20)	(14)	(510)	(28)
Amortization of prior service cost and net actuarial loss and curtailment gain included in net periodic benefit cost, Income Tax Effect	4	3	107	6
Amortization of prior service cost and net actuarial loss and curtailment gain included in net periodic benefit cost, Net-of-Tax Amount	(16)	(11)	(403)	(22)
Other comprehensive loss on unfunded retirement obligations, Before-Tax Amount	(20)	(14)	(116)	(36)
Other comprehensive loss on unfunded retirement obligations, Income Tax Effect	4	3	24	7
Other comprehensive loss on unfunded retirement obligations, Net-of-Tax Amount	(16)	(11)	(92)	(29)
Total other comprehensive loss, Before-Tax Amount	(832)	(6,676)	(3,702)	2,288
Total other comprehensive (loss) income, Income Tax Effect	177	1,400	778	(483)
Total other comprehensive (loss) income, Net-of-Tax Amount	$ (655)	$ (5,276)	$ (2,924)	$ 1,805