ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		$ 2,536,568	$ 2,453,577
Amortization		5,454	5,606
Other current period change		15,762	11,765
Adoption of new accounting standard				$ (100,567)
Ending balance		2,566,804	2,473,975
Currency Translation Adjustments and Other
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(199,713)	(143,773)
Amortization		0	0
Other current period change		15,762	11,765
Adoption of new accounting standard				0
Ending balance		(183,951)	(132,008)
Net Actuarial Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(700,384)	(560,153)
Amortization		5,307	5,517
Other current period change		0	0
Adoption of new accounting standard				(98,987)
Ending balance		(695,077)	(653,623)
Prior Service (Cost)/ Credit
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(11,537)	(6,910)
Amortization		147	89
Other current period change		0	0
Adoption of new accounting standard				(1,580)
Ending balance		(11,390)	(8,401)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(911,634)	(710,836)
Adoption of new accounting standard	[1]			$ (100,567)
Ending balance		$ (890,418)	$ (794,032)

[1] Reflects the impact of adopting ASU No. 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income in 2018, which resulted in a reclassification of stranded tax effects caused by the 2017 Tax Cuts and Jobs Act from accumulated other comprehensive loss to retained earnings.