Long-Term Indebtedness (Details 2) (USD $)					0 Months Ended		0 Months Ended							0 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Apr. 30, 2010	Dec. 21, 2012 Term Loan A	Dec. 31, 2011 Term Loan A	Dec. 21, 2012 Term Loan B	Dec. 31, 2012 Term Loan B	Dec. 31, 2011 Term Loan B	Dec. 31, 2012 HWP Refinance Loan	Dec. 31, 2011 HWP Refinance Loan	Dec. 31, 2010 HWP Refinance Loan	Apr. 30, 2010 HWP Refinance Loan	Dec. 21, 2012 Senior unsecured 2021 Notes	Dec. 31, 2012 Senior unsecured 2021 Notes	Dec. 31, 2010 Senior Credit Facility	Apr. 30, 2010 Senior Credit Facility	Nov. 30, 2004 Predecessor 2015 Notes
Summary of Long-term debt
Long-term debt	$ 1,413,315,000					$ 75,000,000		$ 582,187,000	$ 860,000,000	$ 31,128,000	$ 31,546,000	$ 31,943,000			$ 800,000,000	$ 950,000,000
Other			1,017,000
Net discount	(8,109,000)	(9,310,000)	(11,806,000)
Long-term debt	1,405,206,000	957,236,000	971,154,000
Less current portion	(6,240,000)	(35,296,000)	(32,959,000)	(34,677,000)
Total long-term debt	1,398,966,000	921,940,000	938,195,000	1,009,233,000
Interest rate, stated percentage														5.25%				4.50%
Maximum borrowing capacity of revolving loan													33,000,000				890,000,000
Debt instrument, additional borrowings amount														800,000,000
Principal amount of other senior notes redeemed					72,200,000		277,800,000
Annual maturities of long-term debt, assuming no acceleration of maturities
2013	6,240,000
2014	6,305,000
2015	6,339,000
2016	6,370,000
2017	34,983,000
Thereafter	1,353,078,000
Total	$ 1,413,315,000					$ 75,000,000		$ 582,187,000	$ 860,000,000	$ 31,128,000	$ 31,546,000	$ 31,943,000			$ 800,000,000	$ 950,000,000