ACQUISITION AND DISPOSITION OF REAL ESTATE AND DISCONTINUED OPERATIONS Acquisitions (Details) (USD $)	3 Months Ended		1 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Apr. 30, 2012 Brooklyn, New York Fund III sqft	Mar. 31, 2013 664 North Michigan Avenue [Member] Chicago Illinois Core Portfolio sqft	Feb. 28, 2013 Shopping Center Brooklyn, New York Fund III	Mar. 31, 2013 Acquisitions in 2013 Preliminary Purchase Price Allocation		Mar. 31, 2013 Acquisitions in 2012 Finalized Purchase Price Allocation	Dec. 31, 2012 Acquisitions in 2012 Preliminary Purchase Price Allocation
Business Acquisition [Line Items]
Square Footage of Real Estate Property (in square feet)			79,526	18,141
Business Acquisition, Cost of Acquired Entity, Purchase Price				$ 86,600,000
Payments to Acquire Notes Receivable	0	17,080,000	18,500,000
Debt instrument face amount			23,000,000
Consolidated Joint Venture, Ownership Percentage					99.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners					1.00%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net
Land						22,182,000	[1]	4,933,000	5,175,000
Buildings and Improvements						83,865,000	[1]	14,587,000	15,525,000
Acquisition-related intangible assets (in Acquired lease intangibles, net)								1,180,000	0
Total consideration						$ 106,047,000	[1]	$ 20,700,000	$ 20,700,000

[1] Represents preliminary allocations for 2013 acquisitions where purchase price allocations have not been finalized.