Impairment (Schedule Of Impairment Charges)(Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Asset Impairment [Line Items]
Other	$ 165,000		$ 0		$ 165,000		$ 0
Total reported in continuing operations	165,000		2,536,000		221,000		9,388,000
Total impairment charges	165,000		5,051,000		457,000		15,074,000
Equity in earnings of real estate joint ventures and partnerships, net	4,729,000		(15,695,000)		9,342,000		(11,620,000)
Net impact of impairment charges	168,000		24,940,000		823,000		34,963,000
Property Marketed For Sale Or Sold [Member]
Asset Impairment [Line Items]
Impairment losses related to property	0	[1]	2,536,000	[1]	56,000	[1]	2,780,000	[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]	0	[2]	0	[2]	6,608,000	[2]
Property Held For Sale Or Sold [Member]
Asset Impairment [Line Items]
Impairment losses related to property	0	[3]	2,515,000	[3]	236,000	[3]	5,686,000	[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	$ 3,000		$ 19,889,000		$ 366,000		$ 19,889,000

[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.