Investments in Unconsolidated Real Estate Joint Ventures Unconsolidated Real Estate Joint Ventures (Details) (USD $)			6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011 Deer Park [Member]		Jun. 30, 2011 Deer Park Warehouse [Member]	Jun. 30, 2011 Wisconsin Dells [Member]	Jun. 30, 2011 Equity Method Investee [Member] SquareFeet
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage			33.30%	[1]		50.00%
Square Footage of Real Estate Property			683,033	[1]	29,253	265,061	0
Equity Method Investments	$ 4,600,000	$ 6,400,000	$ 108,000	[1]		$ 4,300,000	$ 200,000
Joint Venture Debt			$ 269,300,000	[1]	$ 2,300,000	$ 24,300,000	$ 0
Reduction in Investment Percentage for Profits Earned From Leasing Services			33.30%			50.00%

[1] Includes a 29,253 square foot warehouse adjacent to the shopping center with a mortgage note of approximately $2.3 million.