Business Segments (Unaudited) (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014		Dec. 31, 2014
Revenues:
Unaffiliated customers		$ 3,681		$ 5,696		$ 12,082		$ 16,203
Intersegment		0		0		0		0
Production and delivery		2,893		3,152		8,653		8,971
Depreciation, depletion and amortization		888		945		2,717		2,924
Impairment of oil and gas properties		3,652		308		9,442		308
Selling, general and administrative expenses		124		158		429		457
Mining exploration and research expenses		32		29		101		93
Environmental obligations and shutdown costs		37		18		61		100
Net gain on sales of assets		0		(46)		(39)		(46)
Operating income (loss)		(3,945)		1,132		(9,282)		3,396
Interest expense, net		163		158		458		483
Provision for (benefit from) income taxes		(360)		349		(1,742)		1,034
Total Assets		50,383		63,875		50,383		63,875		$ 58,674
Capital expenditures		1,527		1,853		$ 5,055		5,415
Document Period End Date						Sep. 30, 2015
Lower of cost or market inventory adjustments		(91)				$ (154)		0
Mining Operations [Member]
Revenues:
Unaffiliated customers		3,155		4,706		10,487		12,716
Intersegment		0		0		0		0
Production and delivery		2,598		2,880		7,789		8,060
Depreciation, depletion and amortization		434		438		1,241		1,178
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		37		43		118		123
Mining exploration and research expenses		32		29		101		93
Environmental obligations and shutdown costs		36		18		60		100
Net gain on sales of assets				(46)		(39)		(46)
Operating income (loss)		18		1,344		1,217		3,208
Interest expense, net		23		24		69		69
Provision for (benefit from) income taxes		29		359		236		668
Total Assets		38,200		38,049		38,200		38,049
Capital expenditures		846		937		2,540		3,010
North America Copper Mines [Member]
Revenues:
Unaffiliated customers		223		219		716		410
Intersegment		946		1,271		3,193		3,835
Production and delivery		1,028	[1]	902		2,933	[2]	2,558
Depreciation, depletion and amortization		136		133		408		368
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		1		1		4		3
Mining exploration and research expenses		1		2		6		6
Environmental obligations and shutdown costs		3		(5)		3		(5)
Net gain on sales of assets				(14)		(39)		(14)
Operating income (loss)		0		471		594		1,329
Interest expense, net		1		1		3		3
Provision for (benefit from) income taxes		0		0		0		0
Total Assets		8,879		9,431		8,879		9,431
Capital expenditures		94		188		308		815
Charges to Cost of Sales for Inventory Adjustments, Asset Impairments and Restructuring		(133)				(144)
Morenci [Member]
Revenues:
Unaffiliated customers		165		140		451		215
Intersegment		332		428		1,209		1,346
Production and delivery		357		341		1,117		936
Depreciation, depletion and amortization		51		51		157		128
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		1		0		2		1
Mining exploration and research expenses		0		0		0		0
Environmental obligations and shutdown costs		0		0		0		0
Net gain on sales of assets				0		0		0
Operating income (loss)		88		176		384		496
Interest expense, net		1		1		2		2
Provision for (benefit from) income taxes		0		0		0		0
Total Assets		3,720		3,689		3,720		3,689
Capital expenditures		61		158		224		691
Other North America Copper Mines [Member]
Revenues:
Unaffiliated customers		58		79		265		195
Intersegment		614		843		1,984		2,489
Production and delivery		671		561		1,816		1,622
Depreciation, depletion and amortization		85		82		251		240
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		0		1		2		2
Mining exploration and research expenses		1		2		6		6
Environmental obligations and shutdown costs		3		(5)		3		(5)
Net gain on sales of assets				(14)		(39)		(14)
Operating income (loss)		(88)		295		210		833
Interest expense, net		0		0		1		1
Provision for (benefit from) income taxes		0		0		0		0
Total Assets		5,159		5,742		5,159		5,742
Capital expenditures		33		30		84		124
South America Mines [Member]
Revenues:
Unaffiliated customers		425		736		1,320		2,383
Intersegment		13		111		57		393
Production and delivery		344		471		1,004		1,477
Depreciation, depletion and amortization		89		102		236		284
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		1		1		3		5
Mining exploration and research expenses		0		0		0		0
Environmental obligations and shutdown costs		0		0		0		0
Net gain on sales of assets				0		0		0
Operating income (loss)		4		273		134		1,010
Interest expense, net		0		1		1		1
Provision for (benefit from) income taxes		2		142		32		409
Total Assets		10,979		10,727		10,979		10,727
Capital expenditures		437		439		1,339		1,278
Cerro Verde [Member]
Revenues:
Unaffiliated customers		238		295		681		996
Intersegment		13		63		64		150
Production and delivery		177		178		540		538
Depreciation, depletion and amortization		57		41		134		120
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		1		0		2		2
Mining exploration and research expenses		0		0		0		0
Environmental obligations and shutdown costs		0		0		0		0
Net gain on sales of assets				0		0		0
Operating income (loss)		16		139		69		486
Interest expense, net		0		1		1		1
Provision for (benefit from) income taxes		0		47		0		177
Total Assets		9,136		7,006		9,136		7,006
Capital expenditures		421		416		1,296		1,207
Other South America Mines [Member]
Revenues:
Unaffiliated customers		187	[3]	441	[3]	639	[4]	1,387	[4]
Intersegment		0	[3]	48	[3]	(7)	[4],[5]	243	[4]
Production and delivery		167	[1],[3]	293	[3]	464	[2],[4]	939	[4]
Depreciation, depletion and amortization		32	[3]	61	[3]	102	[4]	164	[4]
Impairment of oil and gas properties		0	[3]	0	[3]	0	[4]	0	[4]
Selling, general and administrative expenses		0	[3]	1	[3]	1	[4]	3	[4]
Mining exploration and research expenses		0	[3]	0	[3]	0	[4]	0	[4]
Environmental obligations and shutdown costs		0	[3]	0	[3]	0	[4]	0	[4]
Net gain on sales of assets				0	[3]	0	[4]	0	[4]
Operating income (loss)		(12)	[3]	134	[3]	65	[4]	524	[4]
Interest expense, net		0	[3]	0	[3]	0	[4]	0	[4]
Provision for (benefit from) income taxes		2	[3]	95	[3]	32	[4]	232	[4]
Total Assets	[3]	1,843		3,721		1,843		3,721
Capital expenditures		16	[3]	23	[3]	43	[4]	71	[4]
Charges to Cost of Sales for Inventory Adjustments, Asset Impairments and Restructuring		(11)				(11)
Indonesia - Grasberg [Member]
Revenues:
Unaffiliated customers		557	[6]	1,086	[6]	1,969	[7]	2,071	[7]
Intersegment		52		167		37		175
Production and delivery		417		700		1,311		1,594
Depreciation, depletion and amortization		90		92		238		194
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		24		27		74		73
Mining exploration and research expenses		0		0		0		0
Environmental obligations and shutdown costs		0		0		0		0
Net gain on sales of assets				0		0		0
Operating income (loss)		78		434		383		385
Interest expense, net		0		0		0		0
Provision for (benefit from) income taxes		21		181		145		166
Total Assets		8,965		8,537		8,965		8,537
Capital expenditures		222		243		660		722
Africa - Tenke [Member]
Revenues:
Unaffiliated customers		299		379		991		1,071
Intersegment		29		49		98		102
Production and delivery		209		206		634		556
Depreciation, depletion and amortization		65		58		195		172
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		2		3		8		9
Mining exploration and research expenses		0		0		0		0
Environmental obligations and shutdown costs		0		0		0		0
Net gain on sales of assets				0		0		0
Operating income (loss)		52		161		252		436
Interest expense, net		0		0		0		0
Provision for (benefit from) income taxes		6		36		59		93
Total Assets		5,100		5,010		5,100		5,010
Capital expenditures		69		40		166		100
Molybdenum mines [Member]
Revenues:
Unaffiliated customers		0		0		0		0
Intersegment		83		173		298		469
Production and delivery		86	[1]	86		253	[2]	243
Depreciation, depletion and amortization		26		25		77		71
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		0		0		0		0
Mining exploration and research expenses		0		0		0		0
Environmental obligations and shutdown costs		0		0		0		0
Net gain on sales of assets				0		0		0
Operating income (loss)		(29)		62		(32)		155
Interest expense, net		0		0		0		0
Provision for (benefit from) income taxes		0		0		0		0
Total Assets		2,017		2,089		2,017		2,089
Capital expenditures		3		12		10		45
Charges to Cost of Sales for Inventory Adjustments, Asset Impairments and Restructuring		(5)				(8)
Rod & Refining [Member]
Revenues:
Unaffiliated customers		946		1,219		3,097		3,599
Intersegment		5		8		20		24
Production and delivery		946		1,220		3,097		3,601
Depreciation, depletion and amortization		2		2		7		7
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		0		0		0		0
Mining exploration and research expenses		0		0		0		0
Environmental obligations and shutdown costs		0		0		0		0
Net gain on sales of assets				0		0		0
Operating income (loss)		3		5		13		15
Interest expense, net		0		0		0		0
Provision for (benefit from) income taxes		0		0		0		0
Total Assets		235		282		235		282
Capital expenditures		1		1		2		3
Atlantic Copper Smelting & Refining [Member]
Revenues:
Unaffiliated customers		438		597		1,473		1,808
Intersegment		1		4		12		15
Production and delivery		410		578		1,397		1,784
Depreciation, depletion and amortization		10		11		29		31
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		4		4		13		13
Mining exploration and research expenses		0		0		0		0
Environmental obligations and shutdown costs		0		0		0		0
Net gain on sales of assets				0		0		0
Operating income (loss)		15		8		46		(5)
Interest expense, net		3		3		8		10
Provision for (benefit from) income taxes		0		0		0		0
Total Assets		699		948		699		948
Capital expenditures		10		3		18		9
Other Mining & Eliminations [Member]
Revenues:
Unaffiliated customers	[8]	267		470		921		1,374
Intersegment		(1,129)		(1,783)		(3,715)		(5,013)
Production and delivery		(842)	[1]	(1,283)		(2,840)	[2]	(3,753)
Depreciation, depletion and amortization		16		15		51		51
Impairment of oil and gas properties		0		0		0		0
Selling, general and administrative expenses		5		7		16		20
Mining exploration and research expenses		31		27		95		87
Environmental obligations and shutdown costs		33		23		57		105
Net gain on sales of assets				(32)		0		(32)
Operating income (loss)		(105)		(70)		(173)		(117)
Interest expense, net		19		19		57		55
Provision for (benefit from) income taxes		0		0		0		0
Total Assets		1,326		1,025		1,326		1,025
Capital expenditures		10		11		37		38
Charges to Cost of Sales for Inventory Adjustments, Asset Impairments and Restructuring		(35)				(84)
U.S. Oil & Gas Operations [Member]
Revenues:
Unaffiliated customers		525	[9]	990	[9]	1,594	[10],[11]	3,487	[10],[11]
Intersegment		0		0		0	[11]	0	[11]
Production and delivery		293		273		857	[11]	913	[11]
Depreciation, depletion and amortization		450		504		1,465	[11]	1,736	[11]
Impairment of oil and gas properties		3,480		308		9,270	[11]	308	[11]
Selling, general and administrative expenses		37		55		140	[11]	171	[11]
Mining exploration and research expenses		0		0		0	[11]	0	[11]
Environmental obligations and shutdown costs		0		0		0	[11]	0	[11]
Net gain on sales of assets				0		0	[11]	0	[11]
Operating income (loss)		(3,735)		(150)		(10,138)	[11]	359	[11]
Interest expense, net		51		51		129	[11]	201	[11]
Provision for (benefit from) income taxes		0		0		0	[11]	0	[11]
Total Assets		11,911		25,328		11,911		25,328
Capital expenditures		635	[12]	908	[12]	2,430	[11],[13]	2,392	[11],[13]
Corporate, Other & Eliminations [Member]
Revenues:
Unaffiliated customers		1		0		1		0
Intersegment		0		0		0		0
Production and delivery		2	[1]	(1)		7	[2]	(2)
Depreciation, depletion and amortization		4		3		11		10
Impairment of oil and gas properties		172	[14]	0		172	[14]	0
Selling, general and administrative expenses		50		60		171		163
Mining exploration and research expenses		0		0		0		0
Environmental obligations and shutdown costs		1		0		1		0
Net gain on sales of assets				0		0		0
Operating income (loss)		(228)		(62)		(361)		(171)
Interest expense, net		89		83		260		213
Provision for (benefit from) income taxes		(389)		(10)		(1,978)		366
Total Assets		272		498		272		498
Capital expenditures		46		8		85		13
Charges to Cost of Sales for Inventory Adjustments, Asset Impairments and Restructuring		(2)				(2)
Crude oil and natural gas swaps [Member]
Revenues:
Net mark-to-market gains (losses) on derivative contracts		29		64		$ 87		(56)
Pt Smelting [Member]
Segment Reporting Information [Line Items]
Deferred Intercompany Profit, Percentage						25.00%
Revenues:
Revenues		$ 61		628		$ 704		1,500
Equity Method Investment, Ownership Percentage		25.00%				25.00%
Morocco | Corporate, Other & Eliminations [Member]
Revenues:
Capital expenditures		$ 37	[12]	$ 7	[12]	$ 81	[13]	$ 7	[13]

[1] Includes charges totaling $133 million at North America copper mines for inventory adjustments, impairments and restructuring, $11 million at other South America mines for restructuring, $5 million at Molybdenum mines and $35 million at other mining & eliminations for inventory adjustments and restructuring, and $2 million for restructuring at corporate, other & eliminations.

[2] Includes charges totaling $144 million at North America copper mines for inventory adjustments, impairments and restructuring, $11 million at other South America mines for restructuring, $8 million at Molybdenum mines and $84 million at other mining & eliminations for inventory adjustments and restructuring, and $2 million for restructuring at corporate, other & eliminations.

[3] Third-quarter 2014 includes the results of the Candelaria and Ojos del Salado mining operations, which were sold in November 2014.

[4] For the first nine months of 2014 Other South America Mines include the results of the Candelaria and Ojos del Salado mining operations, which were sold in November 2014.

[5] Includes net reductions for provisional pricing adjustments to prior period open sales. There were no intersegment sales from El Abra for the first nine months of 2015.

[6] Includes PT-FI’s sales to PT Smelting totaling $61 million in third-quarter 2015 and $628 million in third-quarter 2014.

[7] Includes PT-FI’s sales to PT Smelting totaling $704 million for the first nine months of 2015 and $1.5 billion for the first nine months of 2014.

[8] Includes revenues from FCX's molybdenum sales company, which includes sales of molybdenum produced by the Molybdenum mines and by certain of the North and South America copper mines.

[9] Includes net mark-to-market gains associated with crude oil and natural gas derivative contracts totaling $29 million in third-quarter 2015 and $64 million in third-quarter 2014.

[10] Includes net mark-to-market gains (losses) associated with crude oil and natural gas derivative contracts totaling $87 million for the first nine months 2015 and $(56) million for the first nine months of 2014.

[11] The first nine months of 2014 include the results from Eagle Ford, which was sold in June 2014.

[12] Excludes capital expenditures totaling $37 million in third-quarter 2015 and $7 million in third-quarter 2014 primarily related to the Morocco oil and gas properties, which are included in corporate, other & eliminations.

[13] Excludes capital expenditures totaling $81 million for the first nine months of 2015 and $7 million for the first nine months of 2014 primarily related to the Morocco oil and gas properties, which are included in corporate, other & eliminations.

[14] Primarily includes impairment charges for Morocco oil and gas properties.