DERIVATIVE FINANCIAL INSTRUMENTS - Gain (Loss) on Derivatives in Cash Flow Hedging Relationship (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Gain (Loss) on Derivatives in Cash Flow Hedging Relationship
Amount of gains (losses) reclassified from accumulated other comprehensive income (loss) into income (loss) next 12 months			$ 300
Cash flow hedges
Gain (Loss) on Derivatives in Cash Flow Hedging Relationship
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives	$ 291	$ 1,273	3,873	$ 55
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Loss)	(481)	(38)	(799)	(396)
Amount and Location of (Losses) Recognized in Income (Loss) on Derivatives	0	0	0	0
Cash flow hedges \| Foreign currency swaps
Gain (Loss) on Derivatives in Cash Flow Hedging Relationship
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives	190	1,273	3,772	55
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Loss)	(155)	(38)	(473)	(396)
Amount and Location of (Losses) Recognized in Income (Loss) on Derivatives	0	$ 0	0	$ 0
Cash flow hedges \| Interest rate swaps
Gain (Loss) on Derivatives in Cash Flow Hedging Relationship
Amount of Gains (Losses) Deferred in Accumulated Other Comprehensive Income (Loss) on Derivatives	101		101
Amount and Location of Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (Loss)	(326)		(326)
Amount and Location of (Losses) Recognized in Income (Loss) on Derivatives	$ 0		$ 0

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

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The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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