Financial Instruments (Unrealized gains losses) (Details) oz in Thousands, lb in Millions, $ in Millions	3 Months Ended
Mar. 31, 2021 USD ($) lb oz $ / oz $ / lb $ / lb	Mar. 31, 2020 USD ($)
Not Designated as Hedging Instrument [Member] \| Amounts recorded in Sales [Member]
Realized gains (losses):
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net	$ 179	$ (231)
Commodity Contract [Member]
Unrealized gains (losses):
Derivative financial instruments	3	(33)
Hedged item – firm sales commitments	(3)	33
Realized gains (losses):
Matured derivative financial instruments	$ 24	(9)
Commodity Contract [Member] \| Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	66
Derivative, Average Forward Price \| $ / lb	3.73
Copper Forward Contracts [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	23
Derivative, Average Forward Price \| $ / lb	4.09
Copper Forward Contracts [Member] \| Not Designated as Hedging Instrument [Member] \| Amounts recorded in Cost of Sales
Realized gains (losses):
Matured derivative financial instruments	$ (8)	24
Copper \| Not Designated as Hedging Instrument [Member] \| Amounts recorded in Sales [Member]
Realized gains (losses):
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net	$ 207	(238)
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	486
Derivative, Average Forward Price \| $ / lb	3.83
Realized gains (losses):
Derivative Average Market Price \| $ / lb	3.99
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	123
Derivative, Average Forward Price \| $ / lb	3.77
Realized gains (losses):
Derivative Average Market Price \| $ / lb	3.99
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	151
Derivative, Average Forward Price \| $ / oz	1,755
Realized gains (losses):
Derivative Average Market Price \| $ / oz	1,689
gold and other \| Not Designated as Hedging Instrument [Member] \| Amounts recorded in Sales [Member]
Realized gains (losses):
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net	$ (28)	$ 7

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

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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

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

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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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.

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Nominal mass used to calculate payments on a derivative instrument.

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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