Foreign Currency Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Schedule of gains (losses) on foreign currency forward contracts
Net gains (loss) on foreign currency forward contracts	$ (2,715)	$ 1,379	$ (3,055)	$ 30
Cost of Sales [Member]
Schedule of gains (losses) on foreign currency forward contracts
Net gains (loss) on foreign currency forward contracts	2	2	7	32
Selling, General and Administrative Expenses
Schedule of gains (losses) on foreign currency forward contracts
Net gains (loss) on foreign currency forward contracts	$ (2,717)	$ 1,377	$ (3,062)	$ (2)