DERIVATIVES (INCOME STATEMENT CLASSIFICATION) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Sales Revenue Services Net	$ 392,515	$ 349,853	$ 786,871	$ 725,102
Other nonoperating income expense	1,865	(259)	2,663	(11,775)
Designated as Hedging Instruments [Member] \| Foreign Exchange [Member] \| Cash Flow [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain or (loss) recognized in other comprehensive income (loss) - effective portion, net of tax:	(738)	(3,565)	(2,583)	(7,458)
Designated as Hedging Instruments [Member] \| Foreign Exchange [Member] \| Cash Flow [Member] \| Reclassification from accumulated other comprehensive income \| Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Sales Revenue Services Net	(1,011)	(4,883)	(3,538)	(10,215)
Not Designated as Hedging Instruments [Member] \| Foreign Exchange [Member] \| Fair Value [Member] \| Reclassification from accumulated other comprehensive income \| Other income (expense), net
Derivative Instruments, Gain (Loss) [Line Items]
Other nonoperating income expense	$ (1,465)	$ (2,343)	$ (1,217)	$ (5,695)

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

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Amount of income (expense) related to nonoperating activities, classified as other.

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