PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	Mar. 31, 2017		Dec. 31, 2016		Mar. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Total cost	$ 399,381		$ 387,708
Less: accumulated depreciation	(290,404)		(278,619)
Total net book value	108,977	[1]	109,089	[1]	$ 111,748	$ 108,522
Assets held under capital leases (included in the above)	10,449		10,022
Less: accumulated depreciation	(4,802)		(4,316)
Total net book value	5,647		5,706
Land and buildings [Member]
Property, Plant and Equipment [Line Items]
Total cost	92,469		90,988
Assets held under capital leases (included in the above)	3,737		3,684
Machinery, fixtures and equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	210,198		202,110
Assets held under capital leases (included in the above)	6,712		6,338
Other equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	34,566		33,752
Software licenses [Member]
Property, Plant and Equipment [Line Items]
Total cost	57,160		55,542
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Total cost	$ 4,988		$ 5,316

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