ACCUMULATED OTHER COMPREHENSIVE LOSS - Related Tax Effects Allocated to Each Component of Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Loss [Line Items]
Gross Amount	$ 488	$ (4,021)	$ 2,576	$ (4,568)
Tax (provision) benefit attributable to other comprehensive income (loss)	329	560	260	790
Other comprehensive income (loss), net of tax	$ 817	$ (3,461)	2,836	(3,778)
Foreign currency translation adjustments
Accumulated Other Comprehensive Loss [Line Items]
Gross Amount			2,481	(4,935)
Tax (provision) benefit attributable to other comprehensive income (loss)			333	892
Other comprehensive income (loss), net of tax			2,814	(4,043)
Foreign currency hedge
Accumulated Other Comprehensive Loss [Line Items]
Gross Amount			95	367
Tax (provision) benefit attributable to other comprehensive income (loss)			(73)	(102)
Other comprehensive income (loss), net of tax			22	265
Defined benefit pension plans
Accumulated Other Comprehensive Loss [Line Items]
Gross Amount			$ 0	$ 0