Investments In Joint Ventures (Aggregate Balance Sheet And Statement Of Income Data For Unconsolidated Joint Ventures) (Details) (USD $)	3 Months Ended				6 Months Ended	12 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Dec. 31, 2012	Dec. 31, 2012
Investments In Joint Ventures [Abstract]
Total assets	$ 917,800,000	[1]	$ 917,800,000	[1]
Total third-party debt	724,800,000		712,700,000
Total equity	165,500,000		165,200,000
Total revenues	32,500,000	[2]	33,700,000	[2],[3]
Net income (loss)	2,000,000		(1,700,000)
Equity in income	934,000	[4]	366,000	[4]
Properties held for sale by unconsolidated joint venture	102,300,000
Revenues prior to sale of operating properties in unconsolidated joint venture			4,100,000
Revenues from discontinued operations attributable to unconsolidated joint venture			$ 6,800,000
Number of operating properties sold	1				7	11

[1] Includes approximately $102.3 million of assets at March 31, 2013 relating to one joint venture which are under contract to be sold in the second quarter of 2013.

[2] Excludes approximately $6.8 million for the three months ended March 31, 2012 relating to the discontinued operations from the sale of seven operating properties within two of our unconsolidated joint ventures during the third and fourth quarters of 2012.

[3] Includes approximately $4.1 million of revenues related to the acquisition by us of 12 joint ventures in January 2012 and one joint venture in December 2012.

[4] Equity in income excludes our ownership interest of fee income from various property management services provided by us to our joint ventures.