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

Derivative instruments and hedging activities (Narrative) (Details)

v3.5.0.2
Derivative instruments and hedging activities (Narrative) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Dec. 31, 2015
Derivatives, Fair Value [Line Items]          
Gain (loss) on derivative instrument $ 500 $ (600) $ (2,400) $ 3,600  
Other current assets [Member] | Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]          
Derivatives, Fair Value [Line Items]          
Assets derivatives - Notional amount 36,747   36,747   $ 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 41,200   41,200    
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 10,000   10,000    
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 10,400   10,400    
Other current assets [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]          
Derivatives, Fair Value [Line Items]          
Assets derivatives - Notional amount 15,574   15,574   $ 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 $ 15,600   $ 15,600