Commitments and Contingencies - Additional Information (Detail) (USD $)	9 Months Ended	6 Months Ended	12 Months Ended	9 Months Ended			12 Months Ended
	Sep. 30, 2011	Jun. 30, 2009 Attorney Fees California Rent Control Litigation Final Resolution in Favor of Company	Dec. 31, 2010 Attorney Fees Colony Park	Sep. 30, 2011 Hurricane Claim Litigation	Jun. 22, 2007 Hurricane Claim Litigation	Dec. 31, 2010 Maximum Colony Park	Dec. 31, 2010 Colony Park Plaintiff
Loss Contingencies [Line Items]
Award for costs and attorney fee claimed by the company		$ 2,100,000	$ 2,100,000				$ 200,000
Loss award claimed							6,800,000
Number of plaintiff							72
Number of Plaintiff the jury rendered verdicts							6
Number of plaintiff dismissed and not appealed							3
Number of plaintiff dismissed							66
Loss awarded to plaintiff						44,000
Award for costs and attorney fee claimed by plaintiff			800,000				56,000
Claims filed against Aon					11,000,000
Proceeds from insurance	$ 14,700,000			$ 7,400,000