OTHER ASSETS (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Other Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)	$ 215	$ 215
Intangible assetsc	401	402
Investments: [Abstract]
Assurance bond	148	157
Fixed income, equity securities and other	70	66
Disposal group, contingent consideration	96	115
Legally restricted fundsg	213	196
Long-term receivable for taxes	106	290
Materials, Supplies, and Other	19	22
Other	85	134
Total other assets	1,560	1,885
Finite-Lived Intangible Assets, Accumulated Amortization	32	54
Equity in affiliated companies’ net earnings	12	12	$ 8
PT-FI
Investments: [Abstract]
Long-term receivable for taxes	143	178
Cerro Verde
Investments: [Abstract]
Long-term receivable for taxes	190	187
PT Smelting
Investments: [Abstract]
PT Smelting	$ 77	80
Ownership percentage	25.00%
Equity in affiliated companies’ net earnings	$ 39	29
Accounts Receivable, before Allowance for Credit Loss, Current	265	261
NEW MEXICO
Investments: [Abstract]
Legally restricted funds for asset retirement obligations at New Mexico mines	212	196
Disposed of by Sale, Discontinued Operations \| Timok, Lower Zone [Member]
Investments: [Abstract]
Divestiture of Businesses, Deferred Payments Receivable, Demand Amount	$ 12	$ 58

Amount of assurance bond provided for smelter development.

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Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income.

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