QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Footnotes) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								9 Months Ended	12 Months Ended			24 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018
Schedule of Quarterly Financial Information [Line Items]
Production and delivery										$ (11,691)	$ (10,266)	$ (10,687)
Interest expense, net										(945)	(801)	(755)
Provision for (benefit from) income taxes										991	883	371
Net income from continuing operations attributable to noncontrolling interests										(292)	(274)	(227)
Payroll withholding taxes	$ 72									72			$ 72
Metals inventory adjustments			$ 12							4	8	36
Environmental obligations and shutdown costs										57
Net gain on sales of assets	82	$ 70	45	$ 11	$ 15	$ 33	$ 10	$ 23		$ 208	$ 81	649
Net gains on sales of assets (usd per share)										$ 0.14	$ 0.06
Income Tax Credits and Adjustments, Net of Noncontrolling Interest										$ 574
Income Tax Credits and Adjustments, Net of Noncontrolling Interests, Per Share										$ 0.39
Earnings per share attributable to common stockholders related to Tax Reform (usd per share)											$ 0.30
Change in PT-FI tax rates										$ 504	$ 0	0
Tax Cuts and Jobs Act of 2017, provisional income tax expense (benefit)										(123)	(393)	0
Operating income (loss)	316	$ 1,315	$ 1,664	$ 1,459	1,479	928	686	597		$ 4,754	3,690	(2,729)
Freeport Cobalt
Schedule of Quarterly Financial Information [Line Items]
Continuing operations (in dollars per share)										$ 0.02
Net income from continuing operations attributable to noncontrolling interests										$ (30)
Operating income (loss)										50
PT Freeport Indonesia [Member]
Schedule of Quarterly Financial Information [Line Items]
Metals inventory adjustments	43
Cerro Verde Royalty Dispute | Royalty Assessments | Cerro Verde
Schedule of Quarterly Financial Information [Line Items]
Loss contingency, loss In period, attributable to parent										$ (195)	$ (186)		(381)
Continuing operations (in dollars per share)										$ (0.13)	$ 0.13
Production and delivery										$ (14)	$ (203)		(217)
Interest expense, net										(370)	(145)		(515)
Other expense										(22)	0		(22)
Provision for (benefit from) income taxes										(35)	7		(28)
Net income from continuing operations attributable to noncontrolling interests										176	$ 169		$ 345
One-time Termination Benefits | Grasberg Segment [Member]
Schedule of Quarterly Financial Information [Line Items]
Continuing operations (in dollars per share)											$ 0.04
Net income from continuing operations attributable to noncontrolling interests											$ 66
Operating income (loss)											(125)
One-time Termination Benefits | Grasberg Segment [Member] | Operating Income (Loss)
Schedule of Quarterly Financial Information [Line Items]
Production and delivery					8	9	87	21
Minimum Tax Credit Carryforwards [Member]
Schedule of Quarterly Financial Information [Line Items]
Income Tax Credits and Adjustments										632
Federal Income Tax Expense (Benefit), Continuing Operations										76	$ 438
MOEF Framework
Schedule of Quarterly Financial Information [Line Items]
Permit Fees										$ 32
Site Remediation, Reclamation and Closure Costs
Schedule of Quarterly Financial Information [Line Items]
Continuing operations (in dollars per share)										$ 0.04	$ 0.14
Environmental obligations and shutdown costs					$ 157	$ 64	$ (30)	$ 19			$ 210
Indonesia
Schedule of Quarterly Financial Information [Line Items]
Production and delivery	(62)
Operating Segments | South America
Schedule of Quarterly Financial Information [Line Items]
Production and delivery										$ (2,365)	(2,244)	(1,758)
Interest expense, net										(429)	(212)	(82)
Provision for (benefit from) income taxes										268	446	216
Net gain on sales of assets										0	0	0
Operating income (loss)										735	916	618
Operating Segments | South America | Cerro Verde
Schedule of Quarterly Financial Information [Line Items]
Production and delivery										(1,887)	(1,878)	(1,351)
Interest expense, net										(429)	(212)	(82)
Provision for (benefit from) income taxes										253	436	222
Net gain on sales of assets										0	0	0
Operating income (loss)										709	868	626
Operating Segments | South America | Cerro Verde Royalty Dispute | Cerro Verde
Schedule of Quarterly Financial Information [Line Items]
Production and delivery										(14)
Interest expense, net										(370)
Other expense										(22)
Operating Segments | Indonesia | Grasberg Segment [Member]
Schedule of Quarterly Financial Information [Line Items]
Loss contingency, loss In period, attributable to parent										$ (110)
Continuing operations (in dollars per share)										$ 0.08
Production and delivery										$ (1,864)	(1,735)	(1,775)
Interest expense, net										(1)	(4)	0
Provision for (benefit from) income taxes										755	869	442
Loss Contingency, Loss in Period										223
Net gain on sales of assets										0	0	0
Operating income (loss)										2,966	2,028	1,048
Operating Segments | Indonesia | One-time Termination Benefits | Grasberg Segment [Member]
Schedule of Quarterly Financial Information [Line Items]
Production and delivery											(120)
Corporate And Eliminations [Member]
Schedule of Quarterly Financial Information [Line Items]
Production and delivery										3,290	3,118	1,517
Interest expense, net										(486)	(563)	(654)
Provision for (benefit from) income taxes										(33)	(437)	(296)
Net gain on sales of assets										208	81	73
Operating income (loss)										(226)	$ (633)	$ (5,890)
Corporate And Eliminations [Member] | Freeport Cobalt
Schedule of Quarterly Financial Information [Line Items]
Net gain on sales of assets										97
Depreciation Expense on Reclassified Assets	$ (48)									(31)
Tax Authority, In Papau, Indonesia
Schedule of Quarterly Financial Information [Line Items]
Change in PT-FI tax rates										504
Tax Authority, In Papau, Indonesia | Penalties | PT Freeport Indonesia [Member]
Schedule of Quarterly Financial Information [Line Items]
Loss Contingency, Offer to Other Party										$ 69
Cerro Verde Collective Labor Agreement [Member] | Operating Segments | South America | Cerro Verde
Schedule of Quarterly Financial Information [Line Items]
Continuing operations (in dollars per share)										$ (0.02)
Production and delivery									$ 69	$ 69
Cost of Goods Sold, Excluding Depreciation, Depletion and Amortization, Net of Noncontrolling Interest										$ 22