Organization, Basis of Presentation and Significant Accounting Policies (Details)	Sep. 30, 2015 state community home
Organization and Basis of Presentation
Number of operating apartment communities | community	255
Number of apartment homes included in operating apartment communities owned	74,202
Number of states where operating apartment communities owned are located | state	11
Number of communities with apartments under reconstruction | community	8
Number of apartment homes under reconstruction	2,675
Number of owned communities under construction | community	27
Expected number of apartment homes under construction	8,649
Communities under development rights | community	33
Estimated number of apartment homes in communities to be developed	9,752