Derivative Financial Instruments (Schedule Of The Fair Values Of Derivative Instruments) (Details) - Cash Flow Hedging [Member] - Foreign Exchange Contract [Member] - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Asset Derivatives
Asset derivatives	$ 2,569	$ 460
Designated as Hedging Instrument [Member] | Accrued Expenses and Other Current Liabilities [Member]
Liability Derivatives
Liability derivatives	293	3,816
Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Asset Derivatives
Asset derivatives	1,962	2,046
Not Designated as Hedging Instrument [Member] | Accrued Expenses and Other Current Liabilities [Member]
Liability Derivatives
Liability derivatives	$ 329	$ 619