Current report of foreign issuer pursuant to Rules 13a-16 and 15d-16 Amendments

Derivative instruments and hedging activities (Narrative) (Details)

v3.4.0.3
Derivative instruments and hedging activities (Narrative) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Dec. 31, 2015
Derivatives, Fair Value [Line Items]      
Gain (loss) on derivative instrument $ (2,900) $ 4,200  
Other current assets [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]      
Derivatives, Fair Value [Line Items]      
Assets derivatives - Notional amount 31,184   $ 54,586
Other current assets [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Conversion To Euro [Member]      
Derivatives, Fair Value [Line Items]      
Assets derivatives - Notional amount 65,700    
Other current assets [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Conversion To NIS [Member]      
Derivatives, Fair Value [Line Items]      
Assets derivatives - Notional amount 8,600    
Other current assets [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member] | Conversion To Yen [Member]      
Derivatives, Fair Value [Line Items]      
Assets derivatives - Notional amount 10,000    
Other current assets [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]      
Derivatives, Fair Value [Line Items]      
Assets derivatives - Notional amount 21,592   $ 2,700
Other current assets [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member] | Conversion To NIS [Member]      
Derivatives, Fair Value [Line Items]      
Assets derivatives - Notional amount $ 21,600