ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Components of Accumulated Other Comprehensive Income, Net of Tax (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($)
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Balance as of December 31, 2014	$ (8,182)
Other comprehensive loss before reclassifications	(5,167)
Balance as of June 30, 2015	(13,349)
Foreign currency translation adjustments
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Balance as of December 31, 2014	1,053
Other comprehensive loss before reclassifications	(4,937)
Balance as of June 30, 2015	(3,884)
Defined benefit pension plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Balance as of December 31, 2014	(8,462)
Other comprehensive loss before reclassifications	(230)
Balance as of June 30, 2015	(8,692)
Change in unrealized loss on investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Balance as of December 31, 2014	(773)
Other comprehensive loss before reclassifications	0
Balance as of June 30, 2015	$ (773)