Investment In Real Estate Joint Ventures And Partnerships (Schedule Of Combined Condensed Statements Of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Revenues, net									$ 133,975	$ 137,419	$ 138,316
Expenses:
Depreciation and amortization									32,005	34,818	38,242
Interest, net									11,905	11,836	16,076
Operating									24,112	23,876	26,126
Real estate taxes, net									18,839	18,865	17,408
General and administrative									696	623	816
Provision for income taxes									138	112	113
Impairment loss									0	0	1,303
Total									87,695	90,130	100,084
Gain on sale of property	$ 34,800	$ 19,800	$ 48,200	$ 111,400	$ 136,300	$ 38,600	$ 34,200	$ 15,800	207,865	218,611	100,714
Net Income									55,775	59,781	53,421
Equity Method Investments [Member]
Expenses:
Gain on sale of non-operating property									0	0	373
Gain on sale of property									$ 9,495	$ 12,492	$ 14,816