Share Based and Deferred Compensation (Details) (USD $)	9 Months Ended
	Sep. 30, 2011 Property Tenants Year sqft ac Room Buildings
Option activity
Outstanding at January 1, 2011, shares	3,116,611
Granted, shares	603,241
Exercised, shares	(120,179)
Outstanding at September 30, 2011, shares	3,599,673
Vested/Exercisable at September 30, 2011, shares	2,287,729
Outstanding at January 1, 2011, Weighted Average Exercise Price	$ 14.56
Granted, Weighted Average Exercise Price	$ 11.89
Exercised, Weighted Average Exercise Price	$ 2.91
Outstanding at September 30, 2011, Weighted Average Exercise Price	$ 14.50
Vested/Exercisable at September 30, 2011, Weighted Average Exercise Price	$ 17.01
Outstanding at January 1, 2011, Weighted Average Remaining Contractual Term	7.81
Granted, Weighted Average Remaining Contractual Term (in years)	9.43
Outstanding at September 30, 2011, Weighted Average Remaining Contractual Term	7.46
Vested/Exercisable at September 30, 2011, Weighted Average Remaining Contractual Term	6.85
Outstanding at January 1, 2011, Aggregate Intrinsic Value	$ (9,080,625)
Granted, Aggregate Intrinsic Value	$ (2,338,765)
Outstanding at September 30, 2011, Aggregate Intrinsic Value	(23,367,772)
Vested/Exercisable at September 30, 2011, Aggregate Intrinsic Value	$ (20,370,992)