Foreign Currency Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Schedule of gains (losses) on foreign currency forward contracts
Net gains (loss) on foreign currency forward contracts	$ 66	$ (1,375)
Cost of Sales [Member]
Schedule of gains (losses) on foreign currency forward contracts
Net gains (loss) on foreign currency forward contracts	5	12
Selling, General and Administrative Expenses
Schedule of gains (losses) on foreign currency forward contracts
Net gains (loss) on foreign currency forward contracts	$ 61	$ (1,387)