ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Equity, beginning balance	$ 1,209,148
Net other comprehensive income/(loss)	(6,782)	$ 6,911
Equity, ending balance	1,222,979
Income tax expense related to items of other comprehensive income/(loss)	143	138
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Equity, beginning balance	(179,300)	(191,300)
Other comprehensive income/(loss) before reclassifications	(7,200)	6,500
Amounts reclassified from accumulated other comprehensive income/(loss) (1)	0	0
Net other comprehensive income/(loss)	(7,200)	6,500
Equity, ending balance	(186,500)	(184,800)
Pension and Post-Retirement Plan Benefit Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Equity, beginning balance	(41,800)	(40,100)
Other comprehensive income/(loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income/(loss) (1)	400	300
Net other comprehensive income/(loss)	400	300
Equity, ending balance	(41,400)	(39,800)
AOCI Including Portion Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Equity, beginning balance	(221,100)	(231,400)
Other comprehensive income/(loss) before reclassifications	(7,200)	6,500
Amounts reclassified from accumulated other comprehensive income/(loss) (1)	400	300
Net other comprehensive income/(loss)	(6,800)	6,800
Equity, ending balance	$ (227,900)	$ (224,600)