CONTINGENCIES (Tax and Other Matters) (Details) $ in Millions, Rp in Trillions		12 Months Ended					21 Months Ended	24 Months Ended	60 Months Ended
	Jan. 01, 2014	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 IDR (Rp)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 21, 2018	Dec. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Income Tax Examination [Line Items]
Payments for legal settlements			$ 56		$ 53	$ 30
Provision for (benefit from) income taxes			(991)		(883)	(371)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Noncontrolling Interest			(292)		(274)	$ (227)
Long-term receivable for taxes			260		445			$ 260	$ 260
Other assets			$ 2,172		2,273			2,172	2,172
Smelter development export duty, threshold			50.00%	50.00%
Cerro Verde
Income Tax Examination [Line Items]
Stability agreement, term	15 years
Cerro Verde | Tax Year 2012 to Tax Year 2013
Income Tax Examination [Line Items]
Loss contingency, loss in period			$ 14
Provision for (benefit from) income taxes			17
Cerro Verde Royalty Dispute | Cerro Verde | Royalty Assessments
Income Tax Examination [Line Items]
Provision for (benefit from) income taxes			35		(7)			28
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Noncontrolling Interest			176		169			345
Cerro Verde Royalty Dispute | Cerro Verde | December 2006 to Tax Year 2013 | Royalty Assessments
Income Tax Examination [Line Items]
Provision for (benefit from) income taxes					129
Judicial Ruling | Cerro Verde Royalty Dispute | Tax Year 2006 To Tax Year 2008 | Royalty Assessments
Income Tax Examination [Line Items]
Payments for legal settlements									188
Judicial Ruling | Cerro Verde Royalty Dispute | December 2006 to Tax Year 2013 | Unfavorable Regulatory Actions
Income Tax Examination [Line Items]
Loss contingency, loss in period					(348)
Loss contingency, loss in period, including tax charges					(186)
Provision for (benefit from) income taxes					(7)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Noncontrolling Interest					$ 169
Judicial Ruling | Cerro Verde Royalty Dispute | Tax Year 2009 to Tax Year 2013 | Unfavorable Regulatory Actions
Income Tax Examination [Line Items]
Loss contingency, loss in period			(420)
Loss contingency, loss in period, including tax charges			(211)
Provision for (benefit from) income taxes			18
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Noncontrolling Interest			191
PT-FI
Income Tax Examination [Line Items]
Other assets			$ 350					350	350
Progressive export duty on copper concentrates, lower threshold, percent			2.50%	2.50%	5.00%
Progressive export duty on copper concentrates, higher threshold, percent			5.00%	5.00%	7.50%		7.50%
Progressive export duty on copper concentrates, change, percent					2.50%
Smelter development export duty, threshold			50.00%	50.00%
Restricted Cash and Cash Equivalents			$ 144		$ 38			144	144
SUNAT | Cerro Verde | October 2011 to September 2012
Income Tax Examination [Line Items]
Tax refund, requested			57					57	57
SUNAT | Cerro Verde
Income Tax Examination [Line Items]
Long-term receivable for taxes			386					386	386
Increase (decrease) in income taxes receivable			203					203	203
Tax Authority, In Papau, Indonesia | PT-FI | Penalties
Income Tax Examination [Line Items]
Loss Contingency, Offer to Other Party			69
Tax Authority, In Papau, Indonesia | PT-FI | January 2016 through April 2017
Income Tax Examination [Line Items]
Loss contingency, estimate of possible loss			$ 48		80			$ 48	$ 48
Change in loss contingency, percent			40.00%					40.00%	40.00%
Tax Authority, In Papau, Indonesia | PT-FI | August 2015 through March 2018
Income Tax Examination [Line Items]
Loss contingency, estimate of possible loss			$ 174					$ 174	$ 174
Tax Authority, In Papau, Indonesia | PT-FI | August 2015 through March 2018 | Penalties
Income Tax Examination [Line Items]
Loss contingency, estimate of possible loss			87					87	87
Loss Contingency, Offer to Other Party			69	Rp 1
Tax Authority, In Papau, Indonesia | PT-FI | Tax Years 2013 to 2017
Income Tax Examination [Line Items]
Loss contingency, estimate of possible loss			251					251	251
Indonesian Supreme Court | PT-FI | The year 2005 and the year 2007
Income Tax Examination [Line Items]
Loss contingency, loss in period			(61)
Cerro Verde
Income Tax Examination [Line Items]
Long-term receivable for taxes			183		185			183	183
PT-FI
Income Tax Examination [Line Items]
Long-term receivable for taxes			493		417			493	493
FCX | Cerro Verde | Tax Year 2012 to Tax Year 2013
Income Tax Examination [Line Items]
Loss contingency, loss in period, including tax charges			16
Noncontrolling Interests | Cerro Verde | Tax Year 2012 to Tax Year 2013
Income Tax Examination [Line Items]
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Noncontrolling Interest			(15)
Income and Other Tax Receivables | PT-FI
Income Tax Examination [Line Items]
Restricted Cash and Cash Equivalents			15					15	15
Other Current Assets | PT-FI
Income Tax Examination [Line Items]
Restricted Cash and Cash Equivalents			7		22			7	7
Other Assets | PT-FI
Income Tax Examination [Line Items]
Restricted Cash and Cash Equivalents			$ 122		$ 16			$ 122	$ 122
Scenario, Forecast [Member] | Annual Surface Water Tax Payments [Member] | PT-FI
Income Tax Examination [Line Items]
Acquire water systems		$ 15