Variable Interest Entities VIE Considerations (Details) (USD $)	3 Months Ended	6 Months Ended
	Mar. 31, 2010 installments	Jun. 30, 2012 limited
Available-for-Sale Securities, Ownership Percentage		100.00%
Number of Variable Interest Entities		5
Consolidated Properties [Member]
Number of Variable Interest Entities		3
Unconsolidated Properties [Member]
Number of Variable Interest Entities		2
Total Owners [Member]
Number of Owners		4
Related party owner [Member]
Number of Owners		2
Ashley Square [Member]
Available-for-Sale Securities, Ownership Percentage		100.00%
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage		99.00%
Cross Creek [Member]
Available-for-Sale Securities, Ownership Percentage		100.00%
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage		99.00%
Number of Partners		3
Partners' Capital Account, Contributions	$ 2,200,000
Number of Installments of Contributed Capital	3
First Installment [Member] | Cross Creek [Member]
Partners' Capital Account, Contributions	$ 563,000
Cross Creek [Member]
Noncontrolling Interest, Ownership Percentage by Parent		1.00%