Impairment (Schedule Of Impairment Charges)(Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Asset Impairment [Line Items]
Total reported in continuing operations	$ 56		$ 6,852
Total impairment charges	292		10,023
Equity in earnings of real estate joint ventures and partnerships, net	4,613		4,075
Net loss attributable to noncontrolling interests	1,467		1,441
Net impact of impairment charges	655		10,023
Property Marketed For Sale Or Sold [Member]
Asset Impairment [Line Items]
Impairment losses related to property	56	[1]	244	[1]
Investments In Real Estate Joint Ventures And Partnerships [Member]
Asset Impairment [Line Items]
Impairment losses related to partially owned real estate joint ventures and partnerships	0	[2]	6,608	[2]
Property Held For Sale Or Sold [Member]
Asset Impairment [Line Items]
Impairment losses related to property	236	[3]	3,171	[3]
Impairment Charges At Equity In Earnings Of Real Estate Joint Ventures And Partnerships, Net [Member]
Asset Impairment [Line Items]
Equity in earnings of real estate joint ventures and partnerships, net	$ 363		$ 0

[1] These charges resulted from changes in management’s plans for these properties, primarily the marketing of these properties for sale. Also included in this caption are impairments associated with dispositions that did not qualify to be reported in discontinued operations.

[2] Amounts reported in 2012 were based on third party offers to buy our interests in industrial real estate joint ventures.

[3] Amounts reported were based on third party offers.