Business (Details)	Sep. 30, 2012
Property/Unit schedule
Wholly Owned Properties	397
Partially Owned Consolidated Properties	19
Military Housing Properties	2
Number of Real Estate Properties	418
Wholly Owned Units	110,520
Partially Owned Consolidated Units	3,475
Military Housing Units	4,991
Number of Units in Real Estate Property	118,986
Business (Textuals) [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	95.50%
Number of States in which Entity Operates	13