Derivative Instruments And Hedging Activities (Schedule Of Derivative Instruments In Consolidated Statements Of Operations) (Details) - Cash Flow Interest Rate Contracts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in OCI	$ 2,641	$ (3,876)	$ 1,085
Gain/(loss) Reclassified From OCI Into Income	$ 3,307	$ 4,947	$ (635)