Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Long-term debt
Long-term debt	$ 1,773,039	$ 1,897,147
Term Loan [Member]
Long-term debt
Long-term debt	0	615,943
2007 asset-backed securitization facility notes due July 2012 [Member]
Long-term debt
Long-term debt	0	6,000
Partnership's term loan facility due November 2015 [Member]
Long-term debt
Long-term debt	150,000	150,000
Partnership's revolving credit facility due November 2015 [Member]
Long-term debt
Long-term debt	395,500	299,000
4.25% convertible senior notes due June 2014 [Member]
Long-term debt
Long-term debt	300,149	281,827
4.75% convertible senior notes due January 2014 [Member]
Long-term debt
Long-term debt	143,750	143,750
7.25% senior notes due December 2018 [Member]
Long-term debt
Long-term debt	350,000	350,000
Other, interest at various rates, collateralized by equipment and other assets
Long-term debt
Long-term debt	140	232
Revolving Credit Facility Due July 2016 [Member]
Long-term debt
Long-term debt	433,500	0
Revolving Credit Facility Due August 2012 [Member]
Long-term debt
Long-term debt	$ 0	$ 50,395

Long-Term Debt (Details) (USD $)
In Thousands, unless otherwise specified

Dec. 31, 2011

Dec. 31, 2010

$ 1,773,039

$ 1,897,147

Term Loan [Member]

615,943

2007 asset-backed securitization facility notes due July 2012 [Member]