Real Estate (Summary Of Real Estate Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Real Estate Properties [Line Items]
Cost	$ 6,064,406	$ 5,608,998
Accumulated Depreciation and Amortization	(1,574,041)	(1,467,050)
Encumbrances	554,442	635,345
Retail and mixed-use properties
Real Estate Properties [Line Items]
Cost	5,929,569	5,478,085
Accumulated Depreciation and Amortization	(1,526,934)	(1,423,682)
Encumbrances	461,106	541,568
Retail properties under capital leases
Real Estate Properties [Line Items]
Cost	124,590	121,069
Accumulated Depreciation and Amortization	(38,509)	(35,179)
Encumbrances	71,620	71,647
Residential
Real Estate Properties [Line Items]
Cost	10,247	9,844
Accumulated Depreciation and Amortization	(8,598)	(8,189)
Encumbrances	$ 21,716	$ 22,130