Derivative Instruments And Hedging Activities - Impact Of Derivative Instruments Not Designated As Hedging Instruments on Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gain Recognized in Earnings on Derivative Instruments	$ 1,050	$ 1,309	$ 1,531	$ 3,375
Foreign Exchange Contracts [Member] | Other Income (Expense), Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain Recognized in Earnings on Derivative Instruments	$ 1,050	$ 1,309	$ 1,531	$ 3,375