OTHER NONOPERATING EXPENSE, NET (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Other Income and Expenses [Abstract]
Interest income	$ 152	$ 144
Foreign currency exchange (loss) / gain, net	(3,077)	4,390
Change in fair value of derivatives (Note 12)	(36)	(228)
Loss on extinguishment of debt	(151)	(109)
Other income, net	15	11
Total other non-operating (expense) / income, net	$ (3,097)	$ 4,208