Debt (Details) (USD $)	12 Months Ended													3 Months Ended	12 Months Ended				12 Months Ended		3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Senior Subordinated Notes 6125 due 2013 [Member]	Dec. 31, 2010 Senior Subordinated Notes 6125 due 2013 [Member]	Dec. 31, 2009 Senior Subordinated Notes 6125 due 2013 [Member]	Dec. 31, 2011 6.875% Senior Subordinated Notes, Due 2015 [Member]	Dec. 31, 2010 6.875% Senior Subordinated Notes, Due 2015 [Member]	Dec. 31, 2009 6.875% Senior Subordinated Notes, Due 2015 [Member]	Dec. 31, 2011 Junior Subordinated Convertible Debentures [Member]	Dec. 31, 2010 Junior Subordinated Convertible Debentures [Member]	Dec. 31, 2009 Junior Subordinated Convertible Debentures [Member]	Dec. 31, 2011 Senior Credit Agreement [Member]	Sep. 30, 2011 Revolving Credit Facility 2010 [Member]	Dec. 31, 2010 Revolving Credit Facility 2010 [Member]	Dec. 31, 2011 Revolving Credit Facility 2011 [Member]	Dec. 31, 2011 Senior Term Loan [Member]	Dec. 31, 2010 Senior Term Loan [Member]	Dec. 31, 2009 2005 Credit Facility [Member]	Dec. 31, 2010 2005 Credit Facility [Member]	Dec. 31, 2010 3.25% Convertible Senior Debentures, Due 2035 [Member]	Dec. 31, 2011 3.25% Convertible Senior Debentures, Due 2035 [Member]	Dec. 31, 2010 3.25% Convertible Senior Debentures, Due 2035 [Member]	Dec. 31, 2009 3.25% Convertible Senior Debentures, Due 2035 [Member]	Dec. 31, 2011 Convertible Senior Subordinated Notes [Member]	Dec. 31, 2010 Convertible Senior Subordinated Notes [Member]	Dec. 31, 2011 7.75% Senior Subordinated Notes, Due 2020 [Member]	Dec. 31, 2010 7.75% Senior Subordinated Notes, Due 2020 [Member]	Dec. 31, 2011 Convertible Subordinated Debt [Member]	Dec. 31, 2010 Convertible Subordinated Debt [Member]	Dec. 31, 2011 Capital Lease Obligations [Member]	Dec. 31, 2010 Capital Lease Obligations [Member]	Dec. 31, 2011 7.75% interest rate swap agreement - fair value hedge [Member]	Dec. 31, 2010 7.75% interest rate swap agreement - fair value hedge [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 2,381,929,000	$ 2,561,461,000		$ 0	$ 250,000,000		$ 0	$ 525,000,000			$ 345,000,000					$ 444,375,000		$ 0			$ 452,500,000	$ 452,500,000	$ 452,500,000				$ 550,000,000	$ 400,000,000	$ 575,000,000	$ 575,000,000	$ 15,054,000	$ 13,961,000
Derivative, Fair Value, Net		(4,290,000)																															35,473,000	(829,000)
Debt Instrument, Unamortized Discount	(422,681,000)	(446,876,000)																			81,663,000	67,701,000	81,663,000						213,655,000	221,495,000
Debt, Current	26,447,000	3,537,000
Long-term Debt, Excluding Current Maturities	1,968,274,000	2,106,758,000
Face Value Of Term Loan And Senior Credit Facility													750,000,000
Line of Credit Facility, Current Borrowing Capacity																300,000,000				800,000,000
Face Value Of Term Loan																	450,000,000
Option To Increase Commitments Under Credit Agreement Maximum																	300,000,000
Line of Credit Facility, Interest Rate Description													The interest rate applicable to the Senior Credit Agreement is, at the Company’s option, a floating base rate plus an applicable margin or the London interbank offered rate (“LIBOR”) plus an applicable margin. Initially, the applicable margins were set at 1.50% with respect to the floating base rate loans and 2.50% with respect to the LIBOR loans. The applicable margins for the Senior Credit Agreement may increase or decrease based on the Company’s consolidated total leverage ratio as specified in the Senior Credit Agreement
Debt Instrument, Interest Rate at Period End																	2.80%
Deferred Finance Costs, Net													15,300,000
Amortization of Financing Costs				200,000	700,000	700,000	1,000,000	1,000,000	1,000,000	200,000	0	0	1,100,000		1,100,000				1,000,000			1,000,000	2,000,000	2,000,000	600,000	100,000
Write Off Of Deferred Debt Issuance Cost	6,012,000	6,636,000	0				4,000,000							2,500,000							4,600,000		4,600,000
Interest Paid	111,100,000	110,300,000	115,600,000
Letters of Credit Outstanding, Amount	$ 12,000,000