PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	Mar. 31, 2020		Dec. 31, 2019		Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total cost	$ 403,770		$ 424,387
Less: accumulated depreciation	(299,482)		(310,486)
Total net book value	104,288	[1]	113,901	[1]	$ 110,347	$ 117,604
Assets held under capital leases (included in the above)	31,661		35,875
Less: accumulated depreciation	(14,654)		(15,799)
Total net book value	17,007		20,076
Land and buildings
Property, Plant and Equipment [Line Items]
Total cost	94,874		100,502
Assets held under capital leases (included in the above)	0		3,914
Machinery, fixtures and equipment
Property, Plant and Equipment [Line Items]
Total cost	204,762		212,810
Assets held under capital leases (included in the above)	31,661		31,961
Other equipment
Property, Plant and Equipment [Line Items]
Total cost	33,984		36,007
Software
Property, Plant and Equipment [Line Items]
Total cost	66,475		70,294
Construction in progress
Property, Plant and Equipment [Line Items]
Total cost	$ 3,675		$ 4,774

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