Acquisitions, Dispositions, and Impairment	6 Months Ended
Jun. 30, 2015
Acquisitions, Dispositions, and Impairment [Abstract]
Acquisitions, Dispositions, and Impairment	5. Acquisitions, Dispositions, and Impairment Acquisitions of Land. In May 2015, we acquired approximately 49.6 acres of land located in Phoenix, Arizona for approximately $36.3 million and in June 2015, we acquired approximately 2.7 acres of land located in Los Angeles, California for approximately $9.5 million. In January 2014, we acquired approximately 2.9 acres of land located in Houston, Texas for approximately $15.6 million and in April 2014, we acquired approximately 7.6 acres of land in Rockville, Maryland for approximately $23.8 million. Acquisition of Non-controlling Ownership Interest. In March 2015, we purchased the remaining 0.01% non-controlling interest in two fully consolidated joint ventures, which own an aggregate of 798 apartment homes located in College Park, Maryland and Irvine, California, for approximately $9.5 million. The acquisitions of the remaining ownership interests were recorded as equity transactions and, as a result, the carrying balances of the non-controlling interest were eliminated and the remaining difference between the purchase price and carrying balance was recorded as a reduction in additional paid-in capital. See Note 13, "Non-controlling Interests," for the effect of changes in ownership interests of these former joint ventures on the equity attributable to common shareholders. Land Holding Dispositions. In March 2015, we sold a land holding adjacent to an operating property in Dallas, Texas for approximately $0.4 million and recognized a gain of approximately $0.1 million. In March 2014, we sold approximately 3.0 acres of land adjacent to a development community in Atlanta, Georgia for approximately $6.3 million and recognized a gain of approximately $0.4 million. In April 2014, we sold approximately 4.7 acres of land adjacent to an operating property in Dallas, Texas for approximately $8.3 million and recognized a gain of approximately $1.4 million. Sale of Operating Properties. In January 2015, we sold two operating properties, which were included in properties held for sale at December 31, 2014, comprised of 1,116 apartment homes located in Tampa, Florida and Austin, Texas for approximately $114.4 million and we recognized a gain of approximately $85.1 million relating to these property sales. Impairment of Land. During the three months ended June 30, 2014, we recognized a $1.2 million impairment charge to the carrying value of a land parcel located in Dallas, Texas. The impairment charge recognized represented the difference between the land holding's carrying value and the estimated fair value based upon the sales contract on this land parcel, which subsequently sold in July 2014. There were no impairment charges recorded for the three and six months ended June 30, 2015.

5. Acquisitions, Dispositions, and Impairment

Acquisitions of Land. In May 2015, we acquired approximately 49.6 acres of land located in Phoenix, Arizona for approximately $36.3 million and in June 2015, we acquired approximately 2.7 acres of land located in Los Angeles, California for approximately $9.5 million. In January 2014, we acquired approximately 2.9 acres of land located in Houston, Texas for approximately $15.6 million and in April 2014, we acquired approximately 7.6 acres of land in Rockville, Maryland for approximately $23.8 million.

Acquisition of Non-controlling Ownership Interest. In March 2015, we purchased the remaining 0.01% non-controlling interest in two fully consolidated joint ventures, which own an aggregate of 798 apartment homes located in College Park, Maryland and Irvine, California, for approximately $9.5 million. The acquisitions of the remaining ownership interests were recorded as equity transactions and, as a result, the carrying balances of the non-controlling interest were eliminated and the remaining difference between the purchase price and carrying balance was recorded as a reduction in additional paid-in capital. See Note 13, "Non-controlling Interests," for the effect of changes in ownership interests of these former joint ventures on the equity attributable to common shareholders.

Land Holding Dispositions. In March 2015, we sold a land holding adjacent to an operating property in Dallas, Texas for approximately $0.4 million and recognized a gain of approximately $0.1 million. In March 2014, we sold approximately 3.0 acres of land adjacent to a development community in Atlanta, Georgia for approximately $6.3 million and recognized a gain of approximately $0.4 million. In April 2014, we sold approximately 4.7 acres of land adjacent to an operating property in Dallas, Texas for approximately $8.3 million and recognized a gain of approximately $1.4 million.

Sale of Operating Properties. In January 2015, we sold two operating properties, which were included in properties held for sale at December 31, 2014, comprised of 1,116 apartment homes located in Tampa, Florida and Austin, Texas for approximately $114.4 million and we recognized a gain of approximately $85.1 million relating to these property sales.

Impairment of Land. During the three months ended June 30, 2014, we recognized a $1.2 million impairment charge to the carrying value of a land parcel located in Dallas, Texas. The impairment charge recognized represented the difference between the land holding's carrying value and the estimated fair value based upon the sales contract on this land parcel, which subsequently sold in July 2014. There were no impairment charges recorded for the three and six months ended June 30, 2015.