Deferred Charges, Goodwill And Other Assets, Net (Schedule Of Cash Flow Hedging, Derivative Financial Instruments On The Income Statement) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Total Amount of Interest Expense presented in the consolidated statements	$ (20,265,000)	$ (22,129,000)	$ (61,795,000)	$ (67,817,000)
Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative		(195,000)		(4,608,000)
Total Amount of Interest Expense presented in the consolidated statements	(20,265,000)	(22,129,000)	(61,795,000)	(67,817,000)
Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member] | Interest Expense [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income		551,000	16,000	3,419,000
Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member] | Interest And Other Investment Income (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative and Reclassification for Forecasted Transactions No Longer Probable of Occurring	$ 0	$ 132,000	$ 0	$ 1,926,000