Related Party Transactions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		7 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Jul. 31, 2012 Montebello [Member]	Sep. 30, 2012 Pacific Urban Residential [Member]
Related Party Transactions [Abstract]
Management and other fees from affiliates including management, property management, development and redevelopment fees from co-investments, net of intercompany amounts eliminated by company	$ 2.9	$ 1.8	$ 7.9	$ 4.2
Related Party Transaction [Line Items]
Related party investment					52.0	14.0
Number Of Units					248
Preferred return rate (in hundredths)						9.50%
Additional future investment in preferred equity to fund renovation costs						4.0
Mortgage loan secured					$ 26.5
Fixed Rate					5.60%
Term of debt					8 years