Real Estate (Summary Of Real Estate Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Real Estate Properties [Line Items]
Cost	$ 6,759,073	$ 6,064,406
Accumulated Depreciation and Amortization	(1,729,234)	(1,574,041)
Encumbrances	542,707	552,704
Retail and mixed-use properties
Real Estate Properties [Line Items]
Cost	6,621,170	5,929,569
Accumulated Depreciation and Amortization	(1,677,938)	(1,526,934)
Encumbrances	449,896	459,454
Retail properties under capital leases
Real Estate Properties [Line Items]
Cost	127,359	124,590
Accumulated Depreciation and Amortization	(42,308)	(38,509)
Encumbrances	71,590	71,620
Residential
Real Estate Properties [Line Items]
Cost	10,544	10,247
Accumulated Depreciation and Amortization	(8,988)	(8,598)
Encumbrances	$ 21,221	$ 21,630