INCOME TAXES (Narrative) (Details) - USD ($) $ in Millions				12 Months Ended
	Dec. 30, 2019	Dec. 21, 2018	Jan. 01, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Income Taxes [Line Items]
Total income taxes paid to all jurisdictions				$ 610	$ 2,000	$ 702
Tax refunds received from all jurisdictions				306	108	329
Tax Attributes
Foreign tax credits				1,716	1,814
Valuation allowances				4,576	4,507
Valuation allowance, increase (decrease)				(69)
Tax Cuts and Jobs Act of 2017, provisional income tax expense (benefit)				0	(123)	(393)
Tax Cuts and Jobs Act of 2017, deferred tax assets, existing income tax expense (benefit)						272
Tax Cuts and Jobs Act of 2017, change in tax rate, provisional income tax expense (benefit)					29
Tax Cuts and Jobs Act of 2017, change in deferred tax asset valuation allowance				44	1,100
Income (loss) from continuing operation, foreign				593	3,502	2,882
Income (loss) from continuing operations, domestic				(287)	390	20
Change in PT-FI tax rates				$ 0	$ 504	$ 0
U.S. federal statutory tax rate				21.00%	21.00%	35.00%
Interest on income taxes accrued				$ 231	$ 186	$ 22
Unrecognized tax benefits				376	404	390	$ 101
Unrecognized tax benefits that would impact the effective tax rate				282
Unrecognized tax benefits that would impact the effective tax rate, net of tax benefits				150
PT Freeport Indonesia [Member]
Tax Attributes
Change in PT-FI tax rates				0	504	0
Loss Contingency, Loss in Period, Including Tax Charges				304
Valuation allowance for operating loss carryforwards
Tax Attributes
Valuation allowances				2,200
Foreign Tax Credits
Tax Attributes
Valuation allowance, increase (decrease)				(208)
Net Operating Losses
Tax Attributes
Valuation allowance, increase (decrease)				$ (98)
Tax Authority, In Papua, Indonesia
Tax Attributes
U.S. federal statutory tax rate		25.00%
SUNAT | Cerro Verde
Tax Attributes
Foreign income tax rate under new stability agreement				32.00%
Foreign Tax Authority
Tax Attributes
Tax Credit Carryforward, Valuation Allowance				$ 1,700
Foreign Tax Authority | Tax Authority, In Papua, Indonesia | 2019 and thereafter
Tax Attributes
U.S. federal statutory tax rate				25.00%
Profits income tax rate				10.00%
Foreign Tax Authority | Settlement with Taxing Authority [Member] | Tax Years 2012 to 2018
Tax Attributes
Payments for legal settlements	$ 250
Foreign Tax Authority | Tax Authority, Spain
Tax Attributes
Operating Loss Carryforwards				$ 516
Foreign Tax Authority | Tax Authority, In Papau, Indonesia
Tax Attributes
Operating Loss Carryforwards				$ 1,200
Foreign Tax Authority | Chili - Service of Internal Taxes
Tax Attributes
U.S. federal statutory tax rate				35.00%
Foreign Tax Authority | Chili - Service of Internal Taxes | Prior to September 2014 [Member]
Tax Attributes
U.S. federal statutory tax rate				35.00%
Foreign Tax Authority | Chili - Service of Internal Taxes | 2020 and thereafter
Tax Attributes
U.S. federal statutory tax rate				44.50%
Foreign Tax Authority | Chili - Service of Internal Taxes | Tax years 2017 through 2021 [Member]
Tax Attributes
U.S. federal statutory tax rate				35.00%
Foreign Tax Authority | Chili - Service of Internal Taxes | Tax Year 2022 and Thereafter
Tax Attributes
U.S. federal statutory tax rate				44.50%
Foreign Tax Authority | Chili - Service of Internal Taxes | Tax Years 2013 to 2017
Tax Attributes
Mining royalty tax rate				4.00%
Foreign Tax Authority | Chili - Service of Internal Taxes | Tax Years 2018 to 2023 | Minimum
Tax Attributes
Mining royalty tax rate				5.00%
Foreign Tax Authority | Chili - Service of Internal Taxes | Tax Years 2018 to 2023 | Maximum
Tax Attributes
Mining royalty tax rate				14.00%
Foreign Tax Authority | SUNAT | 2014
Tax Attributes
U.S. federal statutory tax rate				30.00%
Dividend tax rate				4.10%
Foreign Tax Authority | SUNAT | 2019 and thereafter
Tax Attributes
U.S. federal statutory tax rate				26.00%
Dividend tax rate				9.30%
Foreign Tax Authority | SUNAT | Tax Year 2017
Tax Attributes
Dividend tax rate			5.00%
Corporate Income Tax Rate			29.50%
Tax Authority, In Papau, Indonesia
Tax Attributes
Change in PT-FI tax rates					(504)
Tax Authority, In Papau, Indonesia | PT Freeport Indonesia [Member]
Tax Attributes
Change in PT-FI tax rates					(482)
Domestic Tax Authority
Tax Attributes
Operating Loss Carryforwards				$ 5,900
Valuation allowances					671
State and Local Jurisdiction
Tax Attributes
Operating Loss Carryforwards				10,800
Alternative Minimum Tax Credit
Tax Attributes
Tax Cuts and Jobs Act of 2017, provisional income tax expense (benefit)					$ 123	$ 121
Reserve for Taxes, Other than Income Taxes [Member]
Tax Attributes
Tax Cuts and Jobs Act of 2017, provisional income tax expense (benefit)				29
Other (expense) benefit | PT Freeport Indonesia [Member]
Tax Attributes
Loss Contingency, Loss in Period, Including Tax Charges				123
Interest expense | PT Freeport Indonesia [Member]
Tax Attributes
Loss Contingency, Loss in Period, Including Tax Charges				78
Income expense (benefit) | PT Freeport Indonesia [Member]
Tax Attributes
Loss Contingency, Loss in Period, Including Tax Charges				$ 103