Summary of Significant Accounting Policies (Details) $ in Thousands	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Number of Real Estate Properties	388
Number of Units in Real Estate Property	108,430
Noncontrolling Interests - Partially Owned Properties	$ 122,368	$ 124,909
Partially Owned Properties [Member]
Number of Real Estate Properties	19
Number of Units in Real Estate Property	3,771
Limited Life Partnership Properties [Member]
Number of Real Estate Properties	6
Noncontrolling Interests - Partially Owned Properties	$ 11,092
Noncontrolling Interests Settlement Value	$ 68,300