ACCUMULATED OTHER COMPREHENSIVE LOSS - Summary of Changes in Accumulated Other Comprehensive Loss Included Within Shareholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Loss [Line Items]
Balance, beginning of period	$ 457,100
Other comprehensive income (loss) before tax	2,088	$ (547)
Tax (provision) benefit attributable to other comprehensive income (loss)	(69)	230
Balance, end of period	436,217
Foreign currency translation adjustments
Accumulated Other Comprehensive Loss [Line Items]
Balance, beginning of period	(30,607)	(21,366)
Other comprehensive income (loss) before tax	1,809	(126)
Tax (provision) benefit attributable to other comprehensive income (loss)	0	124
Balance, end of period	(28,798)	(21,492)
Foreign currency hedge
Accumulated Other Comprehensive Loss [Line Items]
Balance, beginning of period	3,904	3,246
Other comprehensive income (loss) before tax	279	(421)
Tax (provision) benefit attributable to other comprehensive income (loss)	(69)	106
Balance, end of period	4,183	2,825
Defined benefit pension plans
Accumulated Other Comprehensive Loss [Line Items]
Balance, beginning of period	(7,859)	(7,221)
Other comprehensive income (loss) before tax	0	0
Balance, end of period	(7,859)	(7,221)
Tax provision
Accumulated Other Comprehensive Loss [Line Items]
Balance, beginning of period	170	5,545
Tax (provision) benefit attributable to other comprehensive income (loss)	(69)	230
Balance, end of period	101	5,775
Accumulated other comprehensive loss
Accumulated Other Comprehensive Loss [Line Items]
Balance, beginning of period	(34,392)	(19,796)
Other comprehensive income (loss)	2,019	(317)
Balance, end of period	$ (32,373)	$ (20,113)