Supplemental Cash Flow Information (Summary Of Non-Cash Investing And Financing Activities)(Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Noncash or Part Noncash Acquisitions [Line Items]
Accrued property construction costs	$ 7,895	$ 6,412
Exchange of operating partnership units for common shares	0	111
Decrease in equity associated with deferred compensation plan (see Note 1)	48,140	0
Property Acquisitions And Investments In Unconsolidated Real Estate Joint Ventures [Member]
Noncash or Part Noncash Acquisitions [Line Items]
Increase in debt, net	0	20,116
Consolidation of Joint Venture [Member]
Noncash or Part Noncash Acquisitions [Line Items]
Increase in debt, net	48,727	0
Increase in property, net	58,665	0
Increase in restricted deposits and mortgage escrows	30	0
Increase in security deposits	$ 169	$ 0