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.

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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.

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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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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.

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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.

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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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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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Derivative Instruments - Effect on Income (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gain (loss) on derivative
Gains or (losses) recognized in income representing hedge ineffectiveness	$ 16,100,000	$ (22,700,000)	$ (14,500,000)
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 derivative liability positions with credit contingent features		11,800,000	15,200,000
Maximum potential collateral requirements		11,800,000	15,200,000
Collateral posted		0	0
Derivatives designated as hedging instruments \| Fair value hedges
Gain (loss) on derivative
Realized and Unrealized Gain (Loss) on Derivative Instruments		(35,700,000)	(25,300,000)	86,800,000
Realized and Unrealized Gain (Loss) on Hedged Items		13,000,000.0	10,800,000	(70,700,000)
Derivatives designated as hedging instruments \| Fair value hedges \| Commodity contracts \| Revenue
Gain (loss) on derivative
Realized and Unrealized Gain (Loss) on Derivative Instruments		0	0	49,300,000
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		(35,700,000)	(25,300,000)	37,500,000
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		13,000,000.0	10,800,000	(70,700,000)
Derivatives designated as hedging instruments \| Cash flow hedges
Gain (loss) on derivative
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Income (Effective Portion)		(7,900,000)	32,300,000	1,000,000.0
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Effective Portion)		(7,600,000)	38,800,000	1,800,000
Amount of Gain (Loss) Recognized in Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)		(14,800,000)	(4,400,000)	10,800,000
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)		(7,800,000)	(145,800,000)	106,500,000
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Effective Portion)		(41,300,000)	18,100,000	7,200,000
Amount of Gain (Loss) Recognized in Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)		700,000	(13,700,000)	28,600,000
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)		(100,000)	178,100,000	(105,400,000)
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Effective Portion)		33,700,000	20,800,000	(5,300,000)
Amount of Gain (Loss) Recognized in Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)		(15,400,000)	9,400,000	(17,800,000)
Derivatives not designated as hedging instruments
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)		50,800,000	7,300,000	46,300,000
Derivatives not designated as hedging instruments \| Commodity contracts
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)		61,800,000	(1,900,000)	32,700,000
Derivatives not designated as hedging instruments \| Commodity contracts \| Revenue
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)		(500,000)	29,700,000	171,700,000
Derivatives not designated as hedging instruments \| Commodity contracts \| Cost of revenue
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)		62,300,000	(31,600,000)	(139,000,000.0)
Derivatives not designated as hedging instruments \| Foreign currency contracts
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)		(11,000,000.0)	9,200,000	13,600,000
Derivatives not designated as hedging instruments \| Foreign currency contracts \| Revenue
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)		(3,200,000)	10,000,000.0	4,100,000
Derivatives not designated as hedging instruments \| Foreign currency contracts \| Other (expense) income, net
Gain (loss) on derivative
Amount of Realized and Unrealized Gain (Loss)		$ (7,800,000)	$ (800,000)	$ 9,500,000