Long-term Debt Instruments (Details) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended				1 Months Ended			1 Months Ended				1 Months Ended			1 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jul. 31, 2010 Amendment July 2010 - Senior Secured Credit Facility	Sep. 30, 2010 7 7/8% Senior Notes	Nov. 30, 2010 6 5/8% Senior Notes	Jun. 30, 2012 Term Loans - Senior Secured Credit Facility	Nov. 30, 2006 Term Loans - Senior Secured Credit Facility Senior Secured Credit Facility - November 2006	Jul. 31, 2010 Tranche B-1	Jul. 31, 2010 Tranche B-1 Senior Secured Credit Facility - November 2006	May 31, 2011 Tranche B-1 Incremental Agreement May 2011 - Senior Secured Credit Facility	Jul. 31, 2010 Tranche B-2 Amendment July 2010 - Senior Secured Credit Facility	Mar. 31, 2011 Tranche B-3 Amendment March 2011 - Senior Secured Credit Facility	Mar. 31, 2011 Tranche B-1 and Tranche B-2 Amendment March 2011 - Senior Secured Credit Facility	May 31, 2011 Incremental Tranche B-3 Incremental Agreement May 2011 - Senior Secured Credit Facility	Nov. 30, 2006 Revolver - Senior Secured Credit Facility Senior Secured Credit Facility - November 2006	Jul. 31, 2010 Revolver - Senior Secured Credit Facility Amendment July 2010 - Senior Secured Credit Facility	Mar. 31, 2011 Revolver - Senior Secured Credit Facility Amendment March 2011 - Senior Secured Credit Facility
Debt Instrument
Principal Amount						$ 1,000,000,000	$ 1,000,000,000		$ 1,600,000,000					$ 500,000,000		$ 1,000,000,000
Maturity Date						Sep. 01, 2018	Nov. 15, 2020			Nov. 03, 2013			Nov. 03, 2016	Mar. 17, 2018		Mar. 17, 2018			Mar. 17, 2016
Outstanding Principal Amended													1,000,000,000
Proceeds from Issuance						974,000,000	988,100,000							490,200,000
Debt Issuance Fees						26,000,000	11,900,000							9,800,000		7,900,000
Stated Interest Rate						7.875%	6.625%
Maximum Borrowing Capacity																	100,000,000	67,500,000	100,000,000
Basis Spread on Variable Rate											2.25%		3.50%	3.75%	3.821%	3.75%
Periodic Payment - Annual Aggregate Percent of Principal									1.00%
Periodic Payment Amount														1,250,000		2,500,000
Extinguishment of Debt, Amount												535,800,000
Loss on extinguishment of debt	0	9,536,000	0	9,536,000	0							9,500,000
Net Proceeds from Issuance and Repayment of Debt																455,500,000
Weighted Average Interest Rate								4.605%
Capital Lease Obligations, Current	9,900,000		9,900,000
Capital Lease Obligations, Noncurrent	$ 300,700,000		$ 300,700,000