Discontinued Operations - Additional Information (Detail)	6 Months Ended	12 Months Ended
	Jun. 30, 2014 Communities Property	Dec. 31, 2013 Communities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number Of Properties Sold	1	8
Number of owned or owned interests of apartment communities	271
Number of Units in Real Estate Property	83,075
Willow Creek [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Units in Real Estate Property	285
Colonial Promenade Nord du Lac [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Square Footage of Real Estate Property	195,536
Held For Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of owned or owned interests of apartment communities	1