Facility Operating Leases (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Schedule of facility lease expense
Cash basis payment	$ 67,584	$ 66,364	$ 198,968	$ 198,663
Straight-line expense	1,824	2,812	5,006	8,109
Amortization of deferred gain	(1,094)	(1,086)	(3,280)	(3,258)
Facility lease expense	$ 68,314	$ 68,090	$ 200,694	$ 203,514