Deferred Charges, Goodwill And Other Assets, Net (Schedule Of Fair Value Of The Derivative Financial Instruments) (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member] | Deferred Charges, Goodwill And Other Assets [Member] | Cash Flow Hedging [Member]    
Derivative Instruments, Gain (Loss) [Line Items]    
Asset Derivatives $ 8,060 $ 2,847