PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	Jun. 30, 2017		Dec. 31, 2016		Jun. 30, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Total cost	$ 430,199		$ 387,708
Less: accumulated depreciation	(314,217)		(278,619)
Total net book value	115,982	[1]	109,089	[1]	$ 105,644	$ 108,522
Assets held under capital leases (included in the above)	15,023		10,022
Less: accumulated depreciation	(5,628)		(4,316)
Total net book value	9,395		5,706
Land and buildings [Member]
Property, Plant and Equipment [Line Items]
Total cost	100,695		90,988
Assets held under capital leases (included in the above)	3,989		3,684
Machinery, fixtures and equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	226,736		202,110
Assets held under capital leases (included in the above)	11,034		6,338
Other equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	36,407		33,752
Software licenses [Member]
Property, Plant and Equipment [Line Items]
Total cost	64,181		55,542
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Total cost	$ 2,180		$ 5,316

[1] (1) Reflects property, plant and equipment.