COMMITMENTS AND CONTINGENCIES Springfield Town Center Acquisition (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Significant Pending Acquisition [Line Items]
Acquisition costs and other expenses	$ (4,937,000)	$ (1,422,000)	$ (1,936,000)
Letters of Credit Outstanding, Amount	7,100,000
Springfield Town Center [Member]
Schedule of Significant Pending Acquisition [Line Items]
Expected payment to acquire real estate	340,000,000
Acquisition costs and other expenses	(2,700,000)
Letters of Credit Outstanding, Amount	$ 46,500,000
Contribution Agreement Operating Partnership Shares	6,250,000