Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Summary of future capital lease, operating lease and financing lease obligation
Operating Leases, 2013	$ 53,666
Operating Leases, 2014	52,070
Operating Leases, 2015	50,353
Operating Leases, 2016	45,926
Operating Leases, 2017	38,826
Operating Leases, thereafter	210,539
Operating Leases Total	451,380
Capital Leases, 2013	6,067
Capital Leases, 2014	5,963
Capital Leases, 2015	6,036
Capital Leases, 2016	5,894
Capital Leases, 2017	5,918
Capital Leases, thereafter	20,001
Capital Leases, Total	49,879
Capital Leases, Less amounts representing interest ranging from 3.6% to 19.6%	(23,221)
Present value of future minimum lease payments, Capital Leases	26,658
Less current maturities, Capital Leases	(1,941)
Long-term obligations, Capital Leases	24,717
Financing Obligations, 2013	28,300
Financing Obligations, 2014	28,333
Financing Obligations, 2015	28,988
Financing Obligations, 2016	29,415
Financing Obligations, 2017	31,399
Financing Obligations, thereafter	316,289
Financing Obligations, Total	462,724
Financing Obligations, Less amounts representing interest ranging from 3.6% to 19.6%	(264,235)
Present value of future minimum lease payments, Financing Obligations	198,489
Less current maturities, Financing Obligations	(2,481)
Long-term Debt Financing Obligations	$ 196,008