Subsequent Events/Other (Details) $ / shares in Units, $ in Thousands	1 Months Ended	9 Months Ended
	Oct. 30, 2015 USD ($) property $ / shares	Sep. 30, 2015 USD ($) property	Sep. 30, 2014 USD ($)
Other [Line Items]
Acquired Properties | property		1
Apartment Units		202
Purchase Price		$ 158,075
Disposed Properties | property		7
Apartment Units		1,707
Sales Price		$ 464,812
Repayments Of Long-term Debt		184,700
Business Combination, Acquisition Related Costs		200	$ 300
Noncash Project Abandonment Costs		2,322	2,067
Other Expenses		2,500	2,400
Employee Benefits and Share-based Compensation		7,000
Litigation Settlement, Amount		5,800	$ 2,800
Owned Property Management Costs [Member]
Other [Line Items]
Employee Benefits and Share-based Compensation		1,000
General and Administrative Expense [Member]
Other [Line Items]
Employee Benefits and Share-based Compensation		$ 6,000
Subsequent Event [Member]
Other [Line Items]
Acquired Properties | property	2
Apartment Units	343
Purchase Price	$ 132,300
Disposed Properties | property	1
Apartment Units	150
Sales Price	$ 48,500
Repayments Of Long-term Debt	$ 150,000
Starwood Portfolio [Member]
Other [Line Items]
Properties Contracted To Be Disposed | property	72
Units Contracted To Be Disposed	23,262
Sales Price For Commitments To Dispose	$ 5,365,000
Minimum [Member] | Subsequent Event [Member]
Other [Line Items]
Expected dividend | $ / shares	$ 9.00
Maximum [Member] | Subsequent Event [Member]
Other [Line Items]
Expected dividend | $ / shares	$ 11.00