Property And Equipment, Net (Narrative) (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2012	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011
Depreciation expense	$ 32,900,000		$ 31,300,000		$ 65,700,000	$ 62,000,000
Agreement to purchase ground lease			225,000,000
Deposit Assets				45,000,000
Payments to Purchase Ground Lease			180,000,000
Payments to Acquire Property, Plant, and Equipment	44,336,000		95,186,000		78,007,000	122,232,000
Property, Plant and Equipment, Gross, Period Increase (Decrease)		22,000,000
Finite-Lived Intangible Assets, Period Increase (Decrease)		(22,000,000)
Lease Agreements [Member]
Payments to Acquire Intangible Assets	0		173,126,000		0	173,126,000
Land, Buildings and Improvements [Member]
Payments to Acquire Property, Plant, and Equipment		$ 73,900,000	$ 51,900,000