Debt (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Debt Instrument [Line Items]
Extinguishment of Debt, Amount	$ 180,460,000
Long-term Debt, Gross	2,545,511,000		2,545,511,000		2,473,927,000
Gains (Losses) on Extinguishment of Debt			(55,652,000)	(47,558,000)
Debt Related Costs	50,868,000	0	50,868,000	35,092,000
stated liquidation amount of convertible debt	50		50
Interest rate swap agreements	(23,570,000)		(23,570,000)		(46,090,000)
Debt Instrument, Unamortized Discount	(594,090,000)		(594,090,000)		(462,274,000)
Debt, Current	(548,519,000)		(548,519,000)		(27,713,000)
Long-term Debt, Excluding Current Maturities	1,426,472,000		1,426,472,000		2,030,030,000
Debt Instrument, Interest Rate, Stated Percentage	7.75%		7.75%
Letters of Credit Outstanding, Amount	8,000,000		8,000,000
Derivative, Basis Spread on Variable Rate	4.24%		4.24%
Amortization of Financing Costs	900,000	1,300,000	2,800,000	4,300,000
Write off of Deferred Debt Issuance Cost	4,784,000	8,300,000	4,800,000	12,400,000
Current Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	0		0		0
Senior Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	403,750,000		403,750,000		419,688,000
Debt Instrument, Interest Rate, Stated Percentage	1.93%		1.93%
7.75% Senior Subordinated Notes, Due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	400,000,000		400,000,000		550,000,000
Debt Instrument, Repurchased Face Amount	150,000,000		150,000,000
3.75% Convertible Senior Subordinated Notes, due 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	132,417,000		132,417,000		318,054,000
Debt Instrument, Repurchased Face Amount	5,150,000		5,150,000
Debt Instrument, Unamortized Discount	(45,648,000)		(45,648,000)		(113,446,000)
treasury stock method average share price to include dilutive securities			$ 27.11
4.00% Junior Subordinated Convertible Debentures, due 2033 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	345,000,000		345,000,000		345,000,000
Debt instrument, convertible, contingent interest rate	0.125%		0.125%
contingent cash interest paid per stated liquidation amount	0.07
contingent cash interest per stated liquidation amount	0.085		0.085
Debt Instrument, Unamortized Discount	(136,651,000)		(136,651,000)		(138,734,000)
treasury stock method average share price to include dilutive securities			$ 40.82
3.25% Convertible Senior Debentures, Due 2035 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	427,500,000		427,500,000		427,500,000
Debt Instrument, Unamortized Discount	(38,320,000)		(38,320,000)		(49,718,000)
treasury stock method average share price to include dilutive securities			$ 78.74
3.75% Convertible Senior Subordinated Notes Due 2042 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	390,000,000		390,000,000		390,000,000
Debt Instrument, Unamortized Discount	(165,428,000)		(165,428,000)		(160,376,000)
treasury stock method average share price to include dilutive securities			$ 41.50
3.5% Convertible senior subordinated debt [Domain]
Debt Instrument [Line Items]
Long-term Debt, Gross	424,250,000		424,250,000		0
Debt Instrument, Convertible, Conversion Price	$ 70		$ 70
treasury stock method average share price to include dilutive securities			$ 70.00
Debt Instrument, Interest Rate, Stated Percentage	3.50%		3.50%
Capitalized Lease and Other Debt Obligations [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	22,594,000		22,594,000		23,685,000
Other miscellaneous charges [Member]
Debt Instrument [Line Items]
Debt Related Costs	$ 50,900,000			$ 35,100,000