Business Segments (Product Revenue) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue from External Customer [Line Items]
Treatment And Refining Charges Included In Copper Concentrates Revenues	$ (75)	$ (100)	$ (155)	$ (205)
Royalty Expense	(26)	(19)	(46)	(49)
Export duties expense	(16)	(10)	(20)	(27)
Revenue from Contract with Customer, Excluding Assessed Tax	2,875	3,655	5,904	7,327
Revenues	3,054	3,546	5,852	7,338
Sales [Member] \| Not Designated as Hedging Instrument [Member]
Revenue from External Customer [Line Items]
Matured derivative financial instruments	179	(109)	(52)	11
Copper In Concentrates [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	749	1,134	1,598	2,299
Copper Cathode [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,124	959	1,961	1,818
Refined Copper Products [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	303	516	845	1,023
Purchased Copper [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	166	325	401	662
Gold
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	341	305	611	696
Molybdenum
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	194	327	437	615
Other Products Or Services [Member]
Revenue from External Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 115	$ 218	$ 272	$ 495

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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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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Amount of expense related to royalty payments under a contractual arrangement such as payment for mineral and drilling rights and use of technology or intellectual property.

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