Foreign Currency Derivative Instruments (Schedule of Gain and Losses on Underlying Assets and Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
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	$ (19)	$ (1,721)	$ (37)	$ (2,812)