ACCUMULATED OTHER COMPREHENSIVE LOSS - Summary of Changes in Accumulated Other Comprehensive Loss Included Within Shareholders' Equity (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]
Balance, beginning of period			$ 457,100
Other comprehensive income (loss) before tax	$ 488	$ (4,021)	2,576	$ (4,568)
Tax (provision) benefit attributable to other comprehensive income (loss)	329	560	260	790
Balance, end of period	447,099		447,099
Foreign currency translation adjustments
Accumulated Other Comprehensive Loss [Line Items]
Balance, beginning of period			(30,607)	(21,366)
Other comprehensive income (loss) before tax			2,481	(4,935)
Tax (provision) benefit attributable to other comprehensive income (loss)			333	892
Balance, end of period	(28,126)	(26,301)	(28,126)	(26,301)
Foreign currency hedge
Accumulated Other Comprehensive Loss [Line Items]
Balance, beginning of period			3,904	3,246
Other comprehensive income (loss) before tax			95	367
Tax (provision) benefit attributable to other comprehensive income (loss)			(73)	(102)
Balance, end of period	3,999	3,613	3,999	3,613
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)	(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)			260	790
Balance, end of period	430	6,335	430	6,335
Accumulated other comprehensive loss
Accumulated Other Comprehensive Loss [Line Items]
Balance, beginning of period			(34,392)	(19,796)
Other comprehensive income (loss)			2,836	(3,778)
Balance, end of period	$ (31,556)	$ (23,574)	$ (31,556)	$ (23,574)