SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS (Details) (USD $)	6 Months Ended						6 Months Ended	3 Months Ended	6 Months Ended	1 Months Ended	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Operating Partnership, as General Partner or Managing Member	Dec. 31, 2012 Operating Partnership, as General Partner or Managing Member	Jun. 30, 2013 Series A Preferred Stock Operating Partnership, as General Partner or Managing Member	Dec. 31, 2012 Series A Preferred Stock Operating Partnership, as General Partner or Managing Member	Jun. 30, 2013 At The Market Equity Program [Member] Common stock	Jun. 30, 2013 New At The Market Equity Program [Member]	Jun. 30, 2013 New At The Market Equity Program [Member]	Apr. 30, 2013 New At The Market Equity Program [Member] Common stock	Jun. 30, 2013 New At The Market Equity Program [Member] Common stock	Jun. 30, 2013 LTIP Units	Dec. 31, 2012 LTIP Units
Noncontrolling Interest [Line Items]
Gross proceeds from issuance of common stock							$ 125,000,000	$ 20,900,000	$ 77,100,000
Common stock issued during the period							4,900,000.0		2,800,000		700,000.0
Proceeds from issuance of common stock	75,871,000	60,717,000					123,100,000		76,000,000		20,600,000
Stock Issue Program, Authorized Amount										$ 150,000,000
Limited partners' common OP units			224,134	284,097	188	188
Share-based compensation, outstanding (in shares)												367,522	168,357