COMPREHENSIVE INCOME - Schedule of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017
Equity [Abstract]
Net income	$ 13,295	$ 11,376	$ 10,992	$ 3,159	$ 10,835	$ 6,394	$ 35,663	$ 20,388
Foreign currency translation adjustment	(2,353)			10,175			(16,359)	33,724
Change in unrealized gain (loss) on derivatives, net of tax	1,386			207			14,419	(331)
Pension liability adjustment, net of tax	2			(7)			8	(22)
Comprehensive income, net	$ 12,330			$ 13,534			$ 33,731	$ 53,759

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to parent entity.

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Amount, after tax and reclassification, of gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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