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COMMITMENTS AND GUARANTEES (Special Mining License (IUPK)) (Details) - USD ($) $ in Millions	12 Months Ended			21 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 21, 2018	Jan. 01, 2023
Contractual Obligations Mining Contracts [Line Items]
Smelter Development Progress, Higher Threshold, Percent	50.00%
Royalty Expense	$ 165	$ 113	$ 246
Export Duties Expense	92	221	180
Surety Bond
Contractual Obligations Mining Contracts [Line Items]
Assurance Bond, Smelter Development	$ 437
PT Freeport Indonesia [Member]
Contractual Obligations Mining Contracts [Line Items]
Progressive export duty on copper concentrates, lower threshold, percent	2.50%
Progressive export duty on copper concentrates, higher threshold, percent	5.00%			7.50%
Smelter Development Progress, Lower Threshold, Percent	30.00%
Royalty Expense	$ 160	106	238
Export Duties Expense	$ 92	$ 66	$ 180
PT Freeport Indonesia [Member] \| Copper
Contractual Obligations Mining Contracts [Line Items]
Royalty Interest in Future Production	4.00%
PT Freeport Indonesia [Member] \| Gold
Contractual Obligations Mining Contracts [Line Items]
Royalty Interest in Future Production	3.75%
PT Freeport Indonesia [Member] \| Silver
Contractual Obligations Mining Contracts [Line Items]
Royalty Interest in Future Production	3.25%
PT Freeport Indonesia [Member] \| Construction Contracts \| Surety Bond
Contractual Obligations Mining Contracts [Line Items]
Assurance Bond, Smelter Development	$ 148
PT Freeport Indonesia [Member]
Contractual Obligations Mining Contracts [Line Items]
Ownership percentage	48.76%			81.28%
PT Freeport Indonesia [Member] \| PT Indocopper Investama [Member]
Contractual Obligations Mining Contracts [Line Items]
Ownership percentage				9.36%
Tax Authority, In Papua, Indonesia
Contractual Obligations Mining Contracts [Line Items]
Foreign income tax rate under new stability agreement	25.00%
Foreign Profits Tax Rate on Net Income Under New Stability Agreement	10.00%
Forecast [Member] \| PT Freeport Indonesia [Member]
Contractual Obligations Mining Contracts [Line Items]
Ownership percentage					48.76%
Memorandum of Understanding with the Indonesian Government, Indonesia Supreme Court Appeal [Member] \| Indonesia Tax Authority \| PT Freeport Indonesia [Member]
Contractual Obligations Mining Contracts [Line Items]
Progressive export duty on copper concentrates, lower threshold, percent		5.00%
Loss Contingency, Loss in Period		$ 155
Annual Surface Water Tax Payments [Member] \| PT Freeport Indonesia [Member]
Contractual Obligations Mining Contracts [Line Items]
Payments for Other Taxes	$ 15