Deferred Charges, Goodwill And Other Assets, Net (Schedule Of Cash Flow Hedging, Derivative Financial Instruments On The Income Statement) (Details) - Not Designated as Hedging Instrument [Member] - Cash Flow Hedging [Member] - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Interest Expense [Member] | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion) | $ (2,381) | $ (3,398) |
| Interest And Other Investment Income (Loss) [Member] | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion, Reclassification for Forecasted Transactions No Longer Probable of Occurring and Amount Excluded from Effectiveness Testing) | (37) | 631 |
| Interest Rate Swaps [Member] | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion) | $ 2,869 | $ (1,183) |