ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 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	(3,610)		(3,231)
Amounts reclassified from accumulated other comprehensive loss	5,250		17,649
Other comprehensive income (loss), net of tax	1,640	(45,594)	14,418
Ending balance	(309,216)		(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	(3,960)		41,282
Amounts reclassified from accumulated other comprehensive loss	0		0
Other comprehensive income (loss), net of tax	(3,960)		41,282
Ending balance	(92,697)		(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	350		(44,513)
Amounts reclassified from accumulated other comprehensive loss	5,250		17,649
Other comprehensive income (loss), net of tax	5,600		(26,864)
Ending balance	$ (216,519)		$ (222,119)