Intangibles (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2011 Property State Year Province License LeaseRenewal	Sep. 30, 2010	Sep. 30, 2011 Segment Property Year State Province License LeaseRenewal	Sep. 30, 2010	Dec. 31, 2010 Property Year
Intangible Assets:
Above market lease intangibles	$ 203,460,000		$ 203,460,000		$ 13,232,000
In-place and other lease intangibles	618,153,000		618,153,000		133,582,000
Other intangibles	16,453,000		16,453,000		13,649,000
Accumulated amortization	(152,486,000)		(152,486,000)		(100,808,000)
Goodwill	288,196,000		288,196,000		19,901,000
Net Intangible Assets	973,776,000		973,776,000		79,556,000
Remaining weighted average amortization period of lease-related intangible assets in years			19.6		18.5
Intangible Liabilities:
Below market lease intangibles	486,228,000		486,228,000		22,398,000
Other lease intangibles	157,971,000		157,971,000
Accumulated amortization	(26,425,000)		(26,425,000)		(12,495,000)
Net Intangible Liabilities	617,774,000		617,774,000		9,903,000
Remaining weighted average amortization period of lease-related intangible liabilities in years	18.5		18.5		6.9
Intangibles (Textuals) [Abstract]
Net amortization expense	23,900,000	2,300,000	40,000,000	5,700,000
Estimated net amortization of the intangibles during 2012			76,100,000
Estimated net amortization of the intangibles during 2013			18,400,000
Estimated net amortization of the intangibles during 2014			15,000,000
Estimated net amortization of the intangibles during 2015			8,900,000
Estimated net amortization of the intangibles during 2016			$ 7,000,000