DERIVATIVE INSTRUMENTS - Gain/(Loss) Recognized in Income on Derivatives (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on foreign currency contracts	$ (509)	$ 0	$ (301)	$ 0
Foreign currency contracts | Other income (expense), net
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on foreign currency contracts	$ (509)	$ 0	$ (301)	$ 0