SPONSORS AND MANAGEMENT WARRANTS (Details) (USD $)	9 Months Ended			1 Months Ended				1 Months Ended
	Sep. 30, 2011	Sep. 30, 2012	Dec. 31, 2011	Nov. 30, 2010 Sponsors Warrants	Sep. 30, 2012 Sponsors Warrants	Dec. 31, 2011 Sponsors Warrants	Nov. 09, 2010 Sponsors Warrants	Feb. 28, 2011 Management Warrants	Sep. 30, 2012 Management Warrants	Dec. 31, 2011 Management Warrants	Feb. 28, 2011 Management Warrants David R. Weinreb	Feb. 28, 2011 Management Warrants Grant Herlitz	Feb. 28, 2011 Management Warrants Andrew C. Richardson
Sponsors and Management Warrants
Issuance of warrants to purchase common stock (in shares)							8,000,000	2,862,687
Estimated initial value							$ 69,500,000
Exercise price (in dollars per share)							$ 50.00				$ 42.23	$ 42.23	$ 54.50
Exercisable (in shares)							6,100,000
Exercisable upon prior notice (in shares)							1,900,000
Notice period to exercise warrants (in days)				90 days
Initial period during which prior notice is to be given for exercise of warrants				6 years 6 months
Proceeds from issuance of management warrants	2,000,000							19,000,000
Warrant liabilities		$ 290,488,000	$ 127,764,000		$ 230,200,000	$ 102,600,000			$ 60,300,000	$ 25,200,000