Hedging Contracts not designated as hedging instruments (Details) - 30-day euro forward contracts - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Cost of Sales [Member]
Derivative [Line Items]
Unrealized gains (losses) on foreign currency derivative instruments not designated as hedges recorded in Net sales		$ 471		$ 259
Foreign Currency Transaction Gain (Loss), Unrealized	$ 3,602	$ (1,595)	$ (7,342)	$ (3,946)
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Term of Contract			30 days