ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of net (gain) loss	$ 1,442	$ 490
Amortization of unrecognized prior service cost	93	131
Reclassification adjustment, before tax and regulatory adjustments	1,535	621
Regulatory adjustments	(1,535)	(621)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	0	0
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax	(12)	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax	(1)	0
Other comprehensive (income) loss, available-for-sale securities, after reclassification adjustment, before tax	(13)	0
Other Comprehensive Income (Loss), before Tax	(13)	0
Other Comprehensive Income (Loss), Tax	3	0
Other comprehensive income	$ (10)	$ 0