Real Estate (Summary Of Real Estate Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Real Estate Properties [Line Items]
Cost	$ 7,819,472	$ 7,635,061
Accumulated Depreciation and Amortization	(2,059,143)	(1,876,544)
Encumbrances	545,898	563,061
Retail and mixed-use properties
Real Estate Properties [Line Items]
Cost	7,680,653	7,500,929
Accumulated Depreciation and Amortization	(2,000,274)	(1,821,046)
Encumbrances	454,053	470,720
Retail properties under capital leases
Real Estate Properties [Line Items]
Cost	127,719	123,346
Accumulated Depreciation and Amortization	(49,216)	(46,140)
Encumbrances	71,519	71,556
Residential
Real Estate Properties [Line Items]
Cost	11,100	10,786
Accumulated Depreciation and Amortization	(9,653)	(9,358)
Encumbrances	$ 20,326	$ 20,785