ACCUMULATED OTHER COMPREHENSIVE LOSS - Related Tax Effects Allocated to Each Component of Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accumulated Other Comprehensive Loss [Line Items]
Gross Amount	$ 613	$ 3,386	$ (3,955)	$ 8,861
Tax (provision) benefit attributable to other comprehensive income (loss)	202	(1,065)	992	(2,295)
Other comprehensive income (loss), net of tax	$ 815	$ 2,321	(2,963)	6,566
Foreign currency translation adjustments
Accumulated Other Comprehensive Loss [Line Items]
Gross Amount			(4,419)	10,406
Tax (provision) benefit attributable to other comprehensive income (loss)			1,108	(2,894)
Other comprehensive income (loss), net of tax			(3,311)	7,512
Foreign currency hedge
Accumulated Other Comprehensive Loss [Line Items]
Gross Amount			464	(1,598)
Tax (provision) benefit attributable to other comprehensive income (loss)			(116)	610
Other comprehensive income (loss), net of tax			348	(988)
Defined benefit pension plans
Accumulated Other Comprehensive Loss [Line Items]
Gross Amount			0	53
Tax (provision) benefit attributable to other comprehensive income (loss)			0	(11)
Other comprehensive income (loss), net of tax			$ 0	$ 42