Foreign Currency Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Schedule of gains (losses) on foreign currency forward contracts
Net gains (loss) on foreign currency forward contracts	$ (405)	$ 26	$ (339)	$ (1,349)
Cost of Sales [Member]
Schedule of gains (losses) on foreign currency forward contracts
Net gains (loss) on foreign currency forward contracts	0	18	5	30
Selling, General and Administrative Expenses
Schedule of gains (losses) on foreign currency forward contracts
Net gains (loss) on foreign currency forward contracts	$ (405)	$ 8	$ (344)	$ (1,379)