DERIVATIVES AND HEDGING ACTIVITIES: (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Derivative Liabilities Reported in Other Current Liabilities
Total derivatives designated as hedging instruments					$ 3,562
Balance of designated derivative contracts as cash flow hedges and their impact on OCI
Balance at the beginning of the period			$ (3,646)
Amount of gain recognized in OCI (effective portion)			2,822
Amount of gain reclassified from OCI to income (effective portion)			3,010
Balance at the end of the period	$ 2,186		2,186
Foreign currency forward contract
Derivative Asset, Fair Value, Amount Not Offset Against Collateral [Abstract]
Foreign exchange contracts designated as cash flow hedges	2,186		$ 2,186
Derivative Liabilities Reported in Other Current Liabilities
Foreign exchange contracts designated as cash flow hedges					3,562
Notional Disclosures [Abstract]
Expected time to realize the accumulated OCI balance related to foreign exchange contracts			12 months
Foreign currency forward contract | Amount Reclassified from Other Comprehensive Income / Loss | Gains / Losses on Derivatives
Notional Disclosures [Abstract]
(Loss) gain on foreign exchange contracts designated as cash flow hedges	(737)	$ 579	$ (3,010)	$ 1,278
Israeli shekel | Foreign currency forward contract | Long | Designated as Hedging Instrument
Notional Disclosures [Abstract]
Notional value of derivative contracts	$ 82,223		$ 82,223		$ 88,532