Communities Purchased (Detail)	6 Months Ended
	Jun. 30, 2011 Property
Retreat at Magnolia Parke in Gainesville, FL
Business Acquisition [Line Items]
Percentage of ownership in communities	100.00%
Real Estate Acquired, Number of Units	204
Real Estate, Date Purchased	April 20, 2011
Atlantic Crossing in Jacksonville, FL
Business Acquisition [Line Items]
Percentage of ownership in communities	100.00%
Real Estate Acquired, Number of Units	200
Real Estate, Date Purchased	April 29, 2011
Hamptons at Hunton Park in Glen Allen, VA (Richmond)
Business Acquisition [Line Items]
Percentage of ownership in communities	100.00%
Real Estate Acquired, Number of Units	300
Real Estate, Date Purchased	June 1, 2011
Avala at Savannah Quarters in Pooler, GA (Savannah)
Business Acquisition [Line Items]
Percentage of ownership in communities	100.00%
Real Estate Acquired, Number of Units	256
Real Estate, Date Purchased	June 13, 2011
Tattersall at Tapestry Park in Jacksonville, FL
Business Acquisition [Line Items]
Percentage of ownership in communities	100.00%
Real Estate Acquired, Number of Units	279
Real Estate, Date Purchased	June 23, 2011