The average market price for a group of price risk forward or futures contracts, such as gas futures contracts.

No definition available.

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- Definition

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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- Definition

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

+ References

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- Definition

The average forward price on the group of price risk forward or futures contracts, such as gas futures contracts.

+ References

No definition available.

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- Definition

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

+ References

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=84234895&loc=SL5618551-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (a),(c),(d),(e)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Nominal mass used to calculate payments on a derivative instrument.

+ References

No definition available.

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- Definition

Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

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- References

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- References

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Financial Instruments (Unrealized gains losses) (Details) oz in Thousands, lb in Millions, $ in Millions		3 Months Ended
	Mar. 31, 2018 lb oz $ / lb $ / lb $ / oz	Mar. 31, 2018 USD ($) $ / lb $ / lb $ / oz	Mar. 31, 2017 USD ($)
Not Designated as Hedging Instrument [Member] \| Amounts recorded in Sales [Member]
Realized gains (losses):
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net \| $		$ (117)	$ 126
Commodity Contract [Member]
Unrealized gains (losses):
Derivative financial instruments \| $		(15)	(2)
Hedged item – firm sales commitments \| $		15	2
Realized gains (losses):
Matured derivative financial instruments \| $		$ 2	8
Commodity Contract [Member] \| Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	57
Derivative, Average Forward Price	3.10	3.10
Copper Forward Contracts [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	3
Derivative, Average Forward Price	3.09	3.09
Copper Forward Contracts [Member] \| Not Designated as Hedging Instrument [Member] \| Amounts recorded in Cost of Sales
Realized gains (losses):
Matured derivative financial instruments \| $		$ 2	(1)
Copper \| Not Designated as Hedging Instrument [Member] \| Amounts recorded in Sales [Member]
Realized gains (losses):
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net \| $		$ (135)	107
Copper \| Short [Member] \| Embedded Derivative Financial Instruments [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	518
Derivative, Average Forward Price	3.13	3.13
Realized gains (losses):
Derivative Average Market Price	3.04	3.04
Copper \| Long [Member] \| Embedded Derivative Financial Instruments [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	104
Derivative, Average Forward Price	3.13	3.13
Realized gains (losses):
Derivative Average Market Price	3.04	3.04
Gold \| Short [Member] \| Embedded Derivative Financial Instruments [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| oz	311
Derivative, Average Forward Price \| $ / oz	1,325	1,325
Realized gains (losses):
Derivative Average Market Price \| $ / oz	1,327	1,327
gold and other [Member] \| Not Designated as Hedging Instrument [Member] \| Amounts recorded in Sales [Member]
Realized gains (losses):
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net \| $		$ 18	$ 19
Cobalt \| Long [Member] \| Embedded Derivative Financial Instruments [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	8
Derivative, Average Forward Price	30.19	30.19
Realized gains (losses):
Derivative Average Market Price	33.88	33.88