Debt (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Debt Instrument [Line Items]
Gains (Losses) on Extinguishment of Debt			$ (8,419,000)	$ (55,652,000)
Long-term Debt, Gross	2,426,257,000		2,426,257,000		2,500,434,000
Interest rate swap agreements	18,041,000		18,041,000		18,671,000
Debt Instrument, Unamortized Discount	(537,115,000)		(537,115,000)		(573,082,000)
Debt, Current	(495,713,000)		(495,713,000)		(527,204,000)
Long-term Debt, Excluding Current Maturities	1,411,470,000		1,411,470,000		1,418,819,000
Debt Instrument, Interest Rate, Stated Percentage	7.75%		7.75%
Letters of Credit Outstanding, Amount	14,000,000		14,000,000
Derivative, Basis Spread on Variable Rate	4.19%		4.19%
Amortization of Financing Costs	1,000,000	1,000,000	3,000,000	3,000,000
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	382,500,000		382,500,000		398,438,000
Debt Instrument, Interest Rate, Stated Percentage	1.91%		1.91%
7.75% Senior Subordinated Notes, Due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	400,000,000		400,000,000		400,000,000
3.75% Convertible Senior Subordinated Notes, due 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Repurchased Face Amount	52,000,000		52,000,000
Cash Paid for Debt Repurchased			134,000,000
Long-term Debt, Gross	79,979,000		79,979,000		132,408,000
Debt Instrument, Unamortized Discount	(26,178,000)		(26,178,000)		(45,098,000)
treasury stock method average share price to include dilutive securities			$ 26.84
conversion threshold	34.89		34.89
4.00% Junior Subordinated Convertible Debentures, due 2033 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	307,122,000		307,122,000		307,153,000
Debt Instrument, Unamortized Discount	(118,998,000)		(118,998,000)		(121,017,000)
treasury stock method average share price to include dilutive securities			$ 40.82
4.0% Junior Subordinated debt due 2033 [Domain]
Debt Instrument [Line Items]
conversion threshold	53.07		53.07
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	(22,081,000)		(22,081,000)		(34,374,000)
treasury stock method average share price to include dilutive securities			$ 77.88
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	(163,611,000)		(163,611,000)		(164,986,000)
treasury stock method average share price to include dilutive securities			$ 41.05
conversion threshold	53.37		53.37
3.5% Convertible senior subordinated debt [Domain]
Debt Instrument [Line Items]
Long-term Debt, Gross	424,250,000		424,250,000		424,250,000
treasury stock method average share price to include dilutive securities			$ 70.00
Capitalized Lease and Other Debt Obligations [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 14,906,000		$ 14,906,000		$ 20,685,000