Investments in Unconsolidated Joint Ventures (Summary Of Financial Information For Joint Ventures) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Net Investment in Properties			$ 1,045,943		$ 1,061,950
Total Assets	$ 1,338,295		1,338,295		1,375,006
Debt	719,801		719,801		712,690
Total Liabilities	847,814		847,814		869,879
Equity	490,481		490,481		505,127
Our investment in and share of equity in earnings of unconsolidated joint ventures	169,919		169,919		$ 163,477
Revenues			159,336	$ 106,793
Property Operating Expense			(56,603)	(32,869)
Net Operating Income			102,733	73,924
Net Income			31,193	32,545
Investment in and share of net income (loss)	$ 8,886	$ 5,880	$ 23,734	$ 19,592