PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, total cost	$ 387,708		$ 347,711
Less: accumulated depreciation	(278,619)		(239,189)
Total net book value	109,089	[1]	108,522	[1]	$ 114,335
Assets held under capital leases (included in the above)
Assets held under capital leases (included in the above)	10,022		8,451
Less: accumulated depreciation	(4,316)		(3,556)
Total net book value	5,706		4,895
Depreciation of property, plant and equipment	30,190		27,943		$ 32,836
Land and buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, total cost	90,988		92,237
Assets held under capital leases (included in the above)
Assets held under capital leases (included in the above)	3,684		3,805
Machinery, fixtures and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, total cost	202,110		164,503
Assets held under capital leases (included in the above)
Assets held under capital leases (included in the above)	6,338		4,646
Other equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, total cost	33,752		32,314
Software licenses [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, total cost	55,542		55,656
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, total cost	$ 5,316		$ 3,001

[1] Reflects property, plant and equipment.