ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
AOCI Attributable to Parent [Roll Forward]
OCI Before Reclassifications	$ 0	$ (800)
Amounts Reclassified from AOCI	3,200	1,500
Other Comprehensive Income (Loss), Net of Tax	3,230	704
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent [Roll Forward]
Beginning balance	(39,400)	(42,300)
Other Comprehensive Income (Loss), Net of Tax	3,230	704
Ending balance	(36,200)	(41,600)
Qualified Cash Flow Hedging Instruments
AOCI Attributable to Parent [Roll Forward]
Beginning balance	(400)	(400)
OCI Before Reclassifications	0	0
Amounts Reclassified from AOCI	0	0
Other Comprehensive Income (Loss), Net of Tax	0	0
Ending balance	(400)	(400)
Unrealized Gains/(Losses) on Marketable Securities
AOCI Attributable to Parent [Roll Forward]
Beginning balance	(1,200)	400
OCI Before Reclassifications	0	(800)
Amounts Reclassified from AOCI	1,200	0
Other Comprehensive Income (Loss), Net of Tax	1,200	(800)
Ending balance	0	(400)
Defined Benefit Plans
AOCI Attributable to Parent [Roll Forward]
Beginning balance	(37,800)	(42,300)
OCI Before Reclassifications	0	0
Amounts Reclassified from AOCI	2,000	1,500
Other Comprehensive Income (Loss), Net of Tax	2,000	1,500
Ending balance	$ (35,800)	$ (40,800)