Debt (Schedule Of Long-Term Debt Instruments) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Total	5,920.4us-gaap_DebtAndCapitalLeaseObligations	$ 4,766.4us-gaap_DebtAndCapitalLeaseObligations
Less current maturities	(34.8)us-gaap_DebtCurrent	(47.5)us-gaap_DebtCurrent
Total long-term debt	5,885.6us-gaap_LongTermDebtNoncurrent	4,718.9us-gaap_LongTermDebtNoncurrent
4.70% Senior notes due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.70%
Debt instrument maturity period	2021
6.875% Senior notes due 2020 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.875%
Debt instrument maturity period	2020
3.25% Senior notes due 2016 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	3.25%
Debt instrument maturity period	2016
Four Point Five Percent Senior Notes Member [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.50%
Debt instrument maturity period	2024
Five Point Seven Five Percent Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	5.75%
Debt instrument maturity period	2044
8.50% Senior notes due 2019 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	8.50%
Debt instrument maturity period	2019
7.875% Senior notes due 2040 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.875%
Debt instrument maturity period	2040
7.20% Debentures due 2027 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	7.20%
Debt instrument maturity period	2027
4.33% MARAD bonds due 2016 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.33%
Debt instrument maturity period	2016
6.36% MARAD bonds due 2015 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.36%
Debt instrument maturity period	2015
4.65% MARAD bonds due 2020 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	4.65%
Debt instrument maturity period	2020
Reported Value Measurement [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	5,920.4	4,766.4
Reported Value Measurement [Member] \| 4.70% Senior notes due 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	1,479.9	1,477.2
Reported Value Measurement [Member] \| 6.875% Senior notes due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	1,008.2	1,024.8
Reported Value Measurement [Member] \| 3.25% Senior notes due 2016 [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	998.0	996.5
Reported Value Measurement [Member] \| Four Point Five Percent Senior Notes Member [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	624.2	0
Reported Value Measurement [Member] \| Five Point Seven Five Percent Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	622.3	0
Reported Value Measurement [Member] \| 8.50% Senior notes due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	583.8	600.5
Reported Value Measurement [Member] \| 7.875% Senior notes due 2040 [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	381.2	382.6
Reported Value Measurement [Member] \| 7.20% Debentures due 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	149.2	149.1
Reported Value Measurement [Member] \| 4.33% MARAD bonds due 2016 [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	46.6	78.9
Reported Value Measurement [Member] \| 6.36% MARAD bonds due 2015 [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	0	25.3
Reported Value Measurement [Member] \| 4.65% MARAD bonds due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Fair Value Disclosure	27.0	$ 31.5

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities.

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