Related Party Transactions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
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	$ 2.8	$ 1.4	$ 5.2	$ 2.6
Related Party Transaction [Line Items]
Executive Vice President of the Company invested			14.0
Preferred return rate (in hundredths)			9.50%
Montebello, related party [Member]
Related Party Transaction [Line Items]
Executive Vice President of the Company invested			52.0
Number Of Units	248		248
Additional future investment in preferred equity to fund renovation costs	4		4
Mortgage loan secured	$ 26.5		$ 26.5
Fixed Rate	5.60%		5.60%