Facility Operating Leases (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Facility Operating Leases [Abstract]
Cash basis payment	$ 70,896	$ 65,682
Straight-line expense	1,642	1,726
Amortization of deferred gain	(1,093)	(1,093)
Facility lease expense	$ 71,445	$ 66,315

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