ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Equity, beginning balance			$ 948,662
Other comprehensive income/(loss)	$ (14,769)	$ (11,170)	(23,826)	$ (12,780)
Equity, ending balance	1,027,716		1,027,716
Income tax expense related to items of other comprehensive income/(loss)	379	243	899	707
Foreign Currency Translation Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Equity, beginning balance			(179,600)	(152,200)
Other comprehensive income/(loss) before reclassifications			(26,700)	(15,300)
Amounts reclassified from accumulated other comprehensive income/(loss) (1)			0	0
Other comprehensive income/(loss)			(26,700)	(15,300)
Equity, ending balance	(206,300)	(167,500)	(206,300)	(167,500)
Pension and Post-Retirement Plan Benefit Adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Equity, beginning balance			(49,000)	(52,600)
Other comprehensive income/(loss) before reclassifications			0	0
Amounts reclassified from accumulated other comprehensive income/(loss) (1)			3,100	2,700
Other comprehensive income/(loss)			3,100	2,700
Equity, ending balance	(45,900)	(49,900)	(45,900)	(49,900)
AOCI Including Portion Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Equity, beginning balance			(228,600)	(204,800)
Other comprehensive income/(loss) before reclassifications			(26,700)	(15,300)
Amounts reclassified from accumulated other comprehensive income/(loss) (1)			3,100	2,700
Other comprehensive income/(loss)			(23,600)	(12,600)
Equity, ending balance	$ (252,200)	$ (217,400)	$ (252,200)	$ (217,400)