Property Acquisitions (Details Textual) (USD $)	12 Months Ended			3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Jul. 31, 2012	Dec. 31, 2010 In-Place Lease Intangible Assets [Member]	Dec. 31, 2012 In-Place Lease Intangible Assets [Member]	Dec. 31, 2011 In-Place Lease Intangible Assets [Member]	Jul. 31, 2012 Grove At Moscow Idaho Valdosta Georgia [Member]	Jul. 31, 2012 Harrison Street Real Estate [Member]	Dec. 31, 2011 Harrison Street Real Estate Campus Crest [Member]	Dec. 31, 2011 Grove At Huntsville and Grove At Stateboro [Member]	Dec. 31, 2011 Grove At Stateboro Georgia [Member]	Jul. 31, 2012 Grove At Valdosta Georgia [Member]
Business Acquisition, Cost of Acquired Entity, Purchase Price							$ 16,800,000				$ 13,600,000
Company Ownership Percentage			80.00%				49.90%	50.10%	50.10%	49.90%		20.00%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain	3,200,000
Purchase Price Of Land	15,900,000	6,300,000
Depreciation				300,000	1,000,000	900,000
Business Acquisition Preexisting Relationship Gain Loss Recognized On Restatement			$ 6,600,000