Foreign Currency Derivative Instruments (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Schedule of foreign currency gains and losses on underlying assets and liabilities
Net gains (loss) on foreign currency forward contracts were partially offset on assets and liabilities	$ (1,091)	$ (354)
Cost of revenue
Schedule of foreign currency gains and losses on underlying assets and liabilities
Net gains (loss) on foreign currency forward contracts were partially offset on assets and liabilities	133	2
Selling, general and administrative
Schedule of foreign currency gains and losses on underlying assets and liabilities
Net gains (loss) on foreign currency forward contracts were partially offset on assets and liabilities	$ (1,224)	$ (356)