Derivatives and Fair Value Measurements (Details 3) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss)	$ 88.4
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	324.4	$ 0.0
Fair value of asset (liability) positions measured on a recurring basis
Investments in debt and equity securities		61.8
Asset Transfers Into Level 3	335.8
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	(0.2)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included in Other Comprehensive Income (Loss)	215.8
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	(227.0)
Foreign currency forward contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss)	31.7
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	200.7	0.0
Fair value of asset (liability) positions measured on a recurring basis
Derivative assets (liabilities), at fair value, net	(200.7)
Asset Transfers Into Level 3	259.8
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	0.0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included in Other Comprehensive Income (Loss)	103.0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	(162.1)
Commodity swap contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss)	56.7
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	123.7	0.0
Fair value of asset (liability) positions measured on a recurring basis
Asset Transfers Into Level 3	76.0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	(0.2)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included in Other Comprehensive Income (Loss)	112.8
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	(64.9)
Diesel fuel hedge contracts [Member]
Fair value of asset (liability) positions measured on a recurring basis
Derivative assets (liabilities), at fair value, net	(123.7)
Fair Value, Measurements, Recurring [Member]
Fair value of asset (liability) positions measured on a recurring basis
Investments in debt and equity securities	0.0	61.8
Total net financial assets (liabilities)	(324.4)	(515.3)
Fair Value, Measurements, Recurring [Member] \| Foreign currency forward contracts [Member]
Fair value of asset (liability) positions measured on a recurring basis
Derivative assets (liabilities), at fair value, net	(200.7)	(410.0)
Fair Value, Measurements, Recurring [Member] \| Commodity swap contracts [Member]
Fair value of asset (liability) positions measured on a recurring basis
Derivative assets (liabilities), at fair value, net	(123.7)	(167.1)
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member]
Fair value of asset (liability) positions measured on a recurring basis
Investments in debt and equity securities	0.0	26.1
Total net financial assets (liabilities)	0.0	26.1
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Foreign currency forward contracts [Member]
Fair value of asset (liability) positions measured on a recurring basis
Derivative assets (liabilities), at fair value, net	0.0	0.0
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Commodity swap contracts [Member]
Fair value of asset (liability) positions measured on a recurring basis
Derivative assets (liabilities), at fair value, net	0.0	0.0
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member]
Fair value of asset (liability) positions measured on a recurring basis
Investments in debt and equity securities	0.0	35.7
Total net financial assets (liabilities)	0.0	(541.4)
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Foreign currency forward contracts [Member]
Fair value of asset (liability) positions measured on a recurring basis
Derivative assets (liabilities), at fair value, net	0.0	(410.0)
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Commodity swap contracts [Member]
Fair value of asset (liability) positions measured on a recurring basis
Derivative assets (liabilities), at fair value, net	0.0	(167.1)
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member]
Fair value of asset (liability) positions measured on a recurring basis
Investments in debt and equity securities	0.0	0.0
Total net financial assets (liabilities)	(324.4)	0.0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Foreign currency forward contracts [Member]
Fair value of asset (liability) positions measured on a recurring basis
Derivative assets (liabilities), at fair value, net	(200.7)	0.0
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Commodity swap contracts [Member]
Fair value of asset (liability) positions measured on a recurring basis
Derivative assets (liabilities), at fair value, net	$ (123.7)	$ 0.0
Derivative [Member] \| Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit and non-performance risk, level 3 unobservable input as a percentage of overall valuation	36.00%
Derivative [Member] \| Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit and non-performance risk, level 3 unobservable input as a percentage of overall valuation	30.00%
Derivative [Member] \| Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit and non-performance risk, level 3 unobservable input as a percentage of overall valuation	26.00%

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Credit and non-performance risk, level 3 unobservable input as a percentage of overall valuation

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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Amount of unrealized (holding) gain (loss) which is included in the statement of income (or changes in net assets) related to those liabilities still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

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Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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Amount of gain (loss) recognized in other comprehensive income, arising from assets, liabilities and financial instruments classified in shareholders' equity measured at fair value on a recurring basis using unobservable inputs (level 3).

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Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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