Acquisitions, Dispositions, Impairments and Discontinued Operations (Narrative) (Details) (USD $)	1 Months Ended				3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended		1 Months Ended
	Aug. 31, 2014 acre	Jul. 31, 2014 acre	Apr. 30, 2014 acre	Jan. 31, 2014 acre	Sep. 30, 2014	Sep. 30, 2013 acre	Jun. 30, 2014	Sep. 30, 2014	Sep. 30, 2013 acre	Dec. 31, 2013	Mar. 31, 2014 acre	Oct. 31, 2014 Scenario, Forecast [Member]
Acres of land acquired			7.6	2.9
Payments to Acquire Land			$ 23,800,000	$ 15,600,000
Number of operating properties acquired												1
Number of apartment units in wholly owned property acquired												276
Sales price of property purchased												62,600,000
Impairment associated with land holdings					0	0		1,152,000	0
Number of operating properties sold								0		12
Number of Apartment Units in operating Property Disposed										3,931
Acres of land sold	19.2	2.4	4.7			3.7			3.7		3.0
Sales price of land parcels	8,300,000	800,000					14,600,000		6,600,000
Gain on sale of land					$ 1,808,000	$ 0	$ 1,801,000	$ 3,609,000	$ 698,000
Document Period End Date								Sep. 30, 2014