Long-Term Debt (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Partnership's 6% senior notes due April 2021	Mar. 31, 2013 4.25% convertible senior notes due June 2014	Dec. 31, 2012 4.25% convertible senior notes due June 2014	Jan. 31, 2013 4.75% convertible senior notes due January 2014	Dec. 31, 2012 4.75% convertible senior notes due January 2014	Mar. 31, 2013 7.25% senior notes due December 2018	Dec. 31, 2012 7.25% senior notes due December 2018	Mar. 31, 2013 Other, interest at various rates, collateralized by equipment and other assets	Mar. 31, 2013 Revolving credit facility due July 2016	Dec. 31, 2012 Revolving credit facility due July 2016	Dec. 31, 2012 Partnership's revolving credit facility due November 2015	Dec. 31, 2012 Partnership's term loan facility due November 2015	Mar. 31, 2013 Partnership's revolving credit facility due May 2018	Mar. 31, 2013 Partnership's term loan facility due May 2018
Long-term Debt
Long-term debt	$ 1,629,654,000	$ 1,564,923,000	$ 344,548,000	$ 326,228,000	$ 320,673,000		$ 143,750,000	$ 350,000,000	$ 350,000,000	$ 378,000	$ 220,500,000	$ 70,000,000	$ 530,500,000	$ 150,000,000	$ 238,000,000	$ 150,000,000
Interest rate (as a percent)			6.00%	4.25%	4.25%	4.75%	4.75%	7.25%	7.25%
Amount of unamortized discount of notes			$ 5,500,000	$ 28,800,000	$ 34,300,000