RESTRUCTURING - Schedule of Restructuring Liability (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Restructuring Liability Rollforward [Roll Forward]
Restructuring reserve, beginning balance	$ 4,121
Charges payable in cash	(116)
Cash payments	(1,481)
Foreign currency translation	(67)
Restructuring reserve, ending balance	2,457
Employee Severance and Benefit Costs
Restructuring Liability Rollforward [Roll Forward]
Restructuring reserve, beginning balance	3,817
Charges payable in cash	(346)
Cash payments	(1,428)
Foreign currency translation	(67)
Restructuring reserve, ending balance	1,976
Other Exit Costs
Restructuring Liability Rollforward [Roll Forward]
Restructuring reserve, beginning balance	304
Charges payable in cash	230
Cash payments	(53)
Foreign currency translation	0
Restructuring reserve, ending balance	$ 481