Financial Instruments And Risk Management (Gross Notional Amount Of Outstanding Derivative Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative, Remaining Maturity	4 years
Derivative Instruments Designated As Cash Flow Hedges [Member] | Currency Forward Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Currency forward contracts	$ 458,823	$ 471,822	$ 399,068
Derivative Instruments Not Designated As Cash Flow Hedges [Member] | Currency Forward Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Currency forward contracts	$ 205,030	$ 214,086	$ 208,941