Facility Operating Leases (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Facility Operating Leases [Abstract]
Cash basis payment	$ 70,142	$ 67,584	$ 211,195	$ 198,968
Straight-line expense	2,118	1,824	5,324	5,006
Amortization of deferred gain	(1,093)	(1,094)	(3,279)	(3,280)
Facility lease expense	$ 71,167	$ 68,314	$ 213,240	$ 200,694

Rental expense incurred for leased assets including furniture and equipment which has not been recognized in costs and expenses applicable to sales and revenues; for example, cost of goods sold or other operating costs and expenses.

No definition available.

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration