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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Revenues, net									$ 135,258	$ 133,975	$ 137,419
Expenses:
Depreciation and amortization									32,126	32,005	34,818
Interest, net									9,664	11,905	11,836
Operating									25,046	24,112	23,876
Real estate taxes, net									18,070	18,839	18,865
General and administrative									551	696	623
Provision for income taxes									133	138	112
Total									85,590	87,695	90,130
Gain on sale of property	$ 46,000	$ 74,100	$ 52,700	$ 19,200	$ 34,800	$ 19,800	$ 48,200	$ 111,400	189,914	207,865	218,611
Net Income									51,677	55,775	59,781
Equity Method Investments [Member]
Expenses:
Gain on sale of property									$ 2,009	$ 9,495	$ 12,492