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, 2018	Dec. 31, 2017
Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Asset Derivatives
Asset derivatives	$ 44	$ 2,481
Designated as Hedging Instrument [Member] | Accrued Expenses and Other Current Liabilities [Member]
Liability Derivatives
Liability derivatives	3,549	110
Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Asset Derivatives
Asset derivatives	583	17
Not Designated as Hedging Instrument [Member] | Accrued Expenses and Other Current Liabilities [Member]
Liability Derivatives
Liability derivatives	$ 234	$ 704