Financial Instruments (Fair Value Of Derivative Instruments On Consolidated Balance Sheets) (Details) - Not Designated As Hedging Instrument [Member] - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other Non-current Assets [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	$ 3,392	$ 1,616
Other Current Assets [Member] | Foreign Currency Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset derivatives	804	661
Accrued Expenses And Other Current Liabilities [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives	(191)	(124)
Accrued Expenses And Other Current Liabilities [Member] | Foreign Currency Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives	$ (344)	$ (1,130)