ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			$ (310,856)	$ (325,274)	$ (325,274)
Other comprehensive income (loss) before reclassifications			(16,432)		(3,231)
Amounts reclassified from accumulated other comprehensive loss			18,478		17,649
Other comprehensive income (loss), net of tax	$ (11,279)	$ 31,790	2,046	14,383	14,418
Ending balance	(308,810)		(308,810)		(310,856)
Foreign Currency Translation Adjustments, Net [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(88,737)	(130,019)	(130,019)
Other comprehensive income (loss) before reclassifications			(12,990)		41,282
Amounts reclassified from accumulated other comprehensive loss			0
Other comprehensive income (loss), net of tax			(12,990)		41,282
Ending balance	(101,727)		(101,727)		(88,737)
Total Pension and Postretirment Adjustments, Net [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(222,119)	$ (195,255)	(195,255)
Other comprehensive income (loss) before reclassifications			(3,442)		(44,513)
Amounts reclassified from accumulated other comprehensive loss			18,478		17,649
Other comprehensive income (loss), net of tax			15,036		(26,864)
Ending balance	$ (207,083)		$ (207,083)		$ (222,119)