Deferred Charges, Goodwill And Other Assets, Net (Narrative) (Details) - Cash Flow Hedging [Member] - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Designated as Hedging Instrument [Member] | |||
| Derivative Instruments, Gain (Loss) [Line Items] | |||
| Derivative notional amount | $ 350,000,000 | ||
| Ineffective increase to interest expense | 600,000 | $ 0 | $ 0 |
| Estimated additional amount to be reclassified to interest expense | 1,700,000 | ||
| Not Designated as Hedging Instrument [Member] | |||
| Derivative Instruments, Gain (Loss) [Line Items] | |||
| Amount of increase in the fair value of derivatives | $ 2,000 | $ 93,000 | $ 79,000 |