Real Estate Acquisitions and Dispositions - Additional Information (Detail)	Sep. 30, 2014
Business Acquisitions and Dispositions [Line Items]
Number of Units in Real Estate Property	81,137
Belterra [Member]
Business Acquisitions and Dispositions [Line Items]
Equity Method Investment, Ownership Percentage	10.00%
Colonial Village at Charleston Place [Member]
Business Acquisitions and Dispositions [Line Items]
Number of Units in Real Estate Property	214
Greenbrook [Member]
Business Acquisitions and Dispositions [Line Items]
Number of Units in Real Estate Property	1,037
Colonial Village at Inverness [Member]
Business Acquisitions and Dispositions [Line Items]
Number of Units in Real Estate Property	586
Verandas at Southwood [Member]
Business Acquisitions and Dispositions [Line Items]
Number of Units in Real Estate Property	300
Colonial Village at Ashford Place [Member]
Business Acquisitions and Dispositions [Line Items]
Number of Units in Real Estate Property	168
Colonial Village at Huntleigh Woods [Member]
Business Acquisitions and Dispositions [Line Items]
Number of Units in Real Estate Property	233
Belterra [Member]
Business Acquisitions and Dispositions [Line Items]
Number of Units in Real Estate Property	288