XML 101 R77.htm IDEA: XBRL DOCUMENT v3.3.1.900
Segment Information (Textual) (Details) - 12 months ended Dec. 31, 2015
individual in Millions
Total
Property
Communities
States
individual
Segment Reporting Information [Line Items]          
Number of Real Estate Properties   254 254    
Number of states in which apartment units are located (states) | States       15  
Market Population (individuals) | individual         1
Percentage of Total Public Multifamily REIT Units 1.00%        
Period properties owned and stabilized (months) 12 months        
Occupancy Level for Stabilized Communities 90.00%        
Period Properties Stabilized 90 days