Subsequent Events/Other (Details) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended	15 Months Ended
	May 03, 2012	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Mar. 31, 2012
Subsequent Events/Other (Textuals) [Abstract]
Number of Apartment Properties Acquired Subsequent	1
Number Of Apartment Units Acquired Subsequent	511
Value of Properties Acquired Subsequent	$ 230,900,000
Number of Apartment Properties Sold Subsequent	4
Number of consolidated apartment units sold	351
Subsequent Event Sold Consolidated Property	15,550,000
Mortgage Debt In Conjunction With Acquisition Of Property	90,000,000
Issuance Of Units Subsequent	1,081,797
Repayment of mortgage loans	30,800,000
Business Combination, Acquisition Related Costs		1,592,000	481,000
Noncash Project Abandonment Costs		1,034,000	1,683,000
Other Expenses		2,600,000	2,200,000
Settlement Expense		4,200,000
contracted aquisition price				1,325,000,000
contracted acquisition percent				26.50%
Remaining Percentage to be Contracted	26.50%
Remaining Acquisition Cost to be Contracted	1,500,000,000
BreakUpFee	80,000,000
Potential Business Combination Costs					5,500,000
Payments of Merger Related Costs, Financing Activities				2,600,000
Estimates of lost revenue and garage reconstruction		22,800,000
Estimates Of Lost Revenue And Garage Reconstruction After Insurance Reimbursements		13,600,000
Initial insurance proceeds		3,467,109
Fees Related to Ownership Interest in Potential Transaction [Member]
Subsequent Events/Other (Textuals) [Abstract]
Potential Business Combination Costs		$ 1,100,000			$ 2,900,000