Derivative Instruments - Effect on Income (Details) - USD ($)	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Gain (loss) on derivative
Gains or (losses) recognized in income representing hedge ineffectiveness	$ (14,500,000)	$ 16,100,000	$ (18,700,000)
Gains or (losses) that were excluded from the assessment of the effectiveness of fair value hedges	0	0	0
Derivative, credit-risk related contingent features
Net liability position	15,200,000	63,200,000
Additional assets required to be posted should credit-risk contingent feature be triggered	15,200,000	35,100,000
Collateral posted		28,100,000
Derivatives designated as hedging instruments \| Fair value hedges
Gain (loss) on derivative
Realized and Unrealized Gain (Loss) on Derivative Instruments	(25,300,000)	86,800,000	132,200,000
Realized and Unrealized Gain (Loss) on Hedged Items	10,800,000	(70,700,000)	(150,900,000)
Derivatives designated as hedging instruments \| Fair value hedges \| Commodity contracts \| Revenue
Gain (loss) on derivative
Realized and Unrealized Gain (Loss) on Derivative Instruments	0	49,300,000	0
Derivatives designated as hedging instruments \| Fair value hedges \| Commodity contracts \| Cost of revenue
Gain (loss) on derivative
Realized and Unrealized Gain (Loss) on Derivative Instruments	(25,300,000)	37,500,000	132,200,000
Derivatives designated as hedging instruments \| Fair value hedges \| Commodity contracts for inventory hedging \| Revenue
Gain (loss) on derivative
Realized and Unrealized Gain (Loss) on Hedged Items	0	0	0
Derivatives designated as hedging instruments \| Fair value hedges \| Commodity contracts for inventory hedging \| Cost of revenue
Gain (loss) on derivative
Realized and Unrealized Gain (Loss) on Hedged Items	10,800,000	(70,700,000)	(150,900,000)
Derivatives designated as hedging instruments \| Cash flow hedges
Gain (loss) on derivative
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Effective Portion)	32,300,000	1,000,000	0
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)	38,800,000	1,800,000	0
Amount of Gain (Loss) Recognized in Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(4,400,000)	10,800,000	0
Derivatives designated as hedging instruments \| Cash flow hedges \| Commodity contracts \| Revenue
Gain (loss) on derivative
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Effective Portion)	(145,800,000)	106,500,000	0
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)	18,100,000	7,200,000	0
Amount of Gain (Loss) Recognized in Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(13,700,000)	28,600,000	0
Derivatives designated as hedging instruments \| Cash flow hedges \| Commodity contracts \| Cost of revenue
Gain (loss) on derivative
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Effective Portion)	178,100,000	(105,400,000)	0
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)	20,800,000	(5,300,000)	0
Amount of Gain (Loss) Recognized in Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)	9,400,000	(17,800,000)	0
Derivatives not designated as hedging instruments
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)	7,300,000	46,300,000	83,600,000
Derivatives not designated as hedging instruments \| Commodity contracts
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)	(1,900,000)	32,700,000	66,700,000
Derivatives not designated as hedging instruments \| Commodity contracts \| Revenue
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)	29,700,000	171,700,000	64,500,000
Derivatives not designated as hedging instruments \| Commodity contracts \| Cost of revenue
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)	(31,600,000)	(139,000,000)	2,200,000
Derivatives not designated as hedging instruments \| Foreign currency contracts
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)	9,200,000	13,600,000	16,900,000
Derivatives not designated as hedging instruments \| Foreign currency contracts \| Revenue
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)	10,000,000	4,100,000	4,300,000
Derivatives not designated as hedging instruments \| Foreign currency contracts \| Other (expense) income, net
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)	$ (800,000)	$ 9,500,000	$ 12,600,000

The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624258-113959

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Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624258-113959

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- References

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5618551-113959

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

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The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 4C
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-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

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The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Net gain (loss) relating to components of the gain (loss) on the fair value hedging instrument excluded from the assessment of fair value hedge effectiveness. Recognized in earnings.

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Amount of gain (loss)recognized in the income statement from the hedging ineffectiveness of a fair value hedge.

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