Hedging - Derivatives Not Designated as Hedging Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative [Line Items]
(Gains) losses on hedging contracts			$ 1,677
30-day euro forward contracts | Cost of sales
Derivative [Line Items]
(Gains) losses on hedging contracts	(1,678)	3,955	264	818
Gains (losses) from fluctuations in the value of the net monetary assets exposed to euro exchange rates	$ (830)	$ (11,633)	$ (5,052)	$ (7,467)
Not designated as hedging instruments | 30-day euro forward contracts
Derivative [Line Items]
Term of contract			30 days