Financial Instruments And Risk Management (Gross Notional Amount Of Outstanding Derivative Instruments) (Details) - Currency Forward Contracts [Member] - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Derivative Instruments Designated As Cash Flow Hedges [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Currency forward contracts	$ 204,000	$ 161,000	$ 133,500
Derivative Instruments Not Designated As Cash Flow Hedges [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Currency forward contracts	$ 189,159	$ 113,195	$ 81,000