QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) (USD $)	3 Months Ended																7 Months Ended	12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Schedule of Quarterly Financial Information [Line Items]
Revenues	$ 5,235,000,000	[1]	$ 5,696,000,000	[1]	$ 5,522,000,000	[1]	$ 4,985,000,000	[1]	$ 5,885,000,000	[2]	$ 6,165,000,000	[2]	$ 4,288,000,000	[2]	$ 4,583,000,000			$ 21,438,000,000	[1],[3]	$ 20,921,000,000	[2],[3]	$ 18,010,000,000	[3]
Operating income	(3,299,000,000)	[4],[5]	1,132,000,000	[4],[5]	1,153,000,000		1,111,000,000		1,650,000,000	[6],[7]	1,707,000,000	[6]	639,000,000	[6]	1,355,000,000	[6]		97,000,000	[4],[5]	5,351,000,000	[6],[7]	5,814,000,000
Net (loss) income	(2,735,000,000)	[8],[9]	704,000,000	[8],[9]	660,000,000	[8],[9]	626,000,000		959,000,000	[10]	1,048,000,000		610,000,000	[10]	824,000,000			(745,000,000)	[8],[9]	3,441,000,000	[10]	3,980,000,000
Net Income (Loss) Attributable to Noncontrolling Interests and Preferred Dividends	117,000,000		152,000,000		178,000,000		116,000,000		252,000,000		227,000,000		128,000,000		176,000,000			563,000,000		783,000,000
Net income attributable to FCX common stockholders	(2,852,000,000)	[1],[4],[5],[8],[9]	552,000,000	[1],[4],[5],[8],[9]	482,000,000	[1],[8],[9]	510,000,000	[1]	707,000,000	[10],[11],[2],[6],[7]	821,000,000	[2],[6]	482,000,000	[10],[11],[12],[2],[6]	648,000,000	[11],[6]		(1,308,000,000)	[1],[4],[5],[8],[9]	2,658,000,000	[10],[11],[12],[2],[6],[7]	3,041,000,000
Basic net (loss) income per share attributable to FCX common stockholders	$ (2.75)		$ 0.53		$ 0.46		$ 0.49		$ 0.68		$ 0.79		$ 0.49		$ 0.68			$ (1.26)		$ 2.65		$ 3.20
Diluted net (loss) income per share attributable to FCX common stockholders	$ (2.75)	[1],[4],[5],[8],[9]	$ 0.53	[1],[4],[5],[8],[9]	$ 0.46	[1],[8],[9]	$ 0.49	[1]	$ 0.68	[10],[11],[2],[6],[7]	$ 0.79	[2],[6]	$ 0.49	[10],[11],[12],[2],[6]	$ 0.68	[11],[6]		$ (1.26)	[1],[4],[5],[8],[9]	$ 2.64	[10],[11],[12],[2],[6],[7]	$ 3.19
Impairment of oil and gas properties	3,400,000,000		308,000,000														0	3,737,000,000		0		0
Impairment of Oil and Gas Properties, Net of Tax	2,100,000,000		192,000,000															2,300,000,000
Impairment of Oil and Gas Properties, Amount per Share	$ 2.05		$ 0.18															$ 2.24
Goodwill impairment	1,700,000,000																	1,717,000,000		0		0
Goodwill, Impairment Loss, Amount per Share	$ 1.65																	$ 1.65
Gain (Loss) on Disposition of Assets	671,000,000		46,000,000															717,000,000		0		0
Gain (Loss) on Disposition of Assets, Net of Tax	450,000,000		31,000,000															481,000,000
Gain (Loss) on Disposition of Assets, Amount per Share	$ 0.43		$ 0.03															$ 0.46
Income Tax Expense (Benefit), Changes in Deferred Tax Liabilities and Deferred Tax Asset Valuation Allowances	22,000,000		5,000,000		57,000,000													84,000,000		(190,000,000)
Income Tax Expense (Benefit), Changes in Deferred Tax Liabilities and Deferred Tax Asset Valuation Allowances, Amount Per Share	$ 0.02				$ 0.06													$ 0.08
Income Tax Expense (Benefit) Associated with Changes in Foreign Tax Rates and Certain Tax Elections	(17,000,000)		54,000,000															37,000,000
Income Tax Expense (Benefit) Associated with Changes in Foreign Tax Rates and Certain Tax Elections, Portion Attributable to Noncontrolling Interest	11,000,000		7,000,000															18,000,000
Income Tax Expense (Benefit) Associated with Changes in Foreign Tax Rates and Certain Tax Elections, Net of Noncontrolling Interest	(28,000,000)		47,000,000															19,000,000
Income Tax Expense (Benefit) Associated with Changes in Foreign Tax Rates and Certain Tax Elections, Net of Noncontrolling Interest, Per Share	$ (0.03)		$ 0.04															$ 0.02
Extinguishment of Debt, Gain (Loss), Net of Tax	(18,000,000)		17,000,000		4,000,000				7,000,000				5,000,000		(40,000,000)			3,000,000		(28,000,000)
Extinguishment of Debt, Gain (Loss), Per Share, Net of Tax	$ (0.02)		$ 0.02						$ 0.01				$ 0.01		$ (0.04)					$ (0.03)
Business Combination, Acquisition Related Costs									4,000,000		1,000,000		61,000,000		14,000,000					80,000,000
Business Combination, Acquisition Related Costs, Net of Tax									3,000,000		1,000,000		36,000,000		10,000,000					50,000,000
Business Combination, Acquisition Related Costs, Net of Tax, Amount Per Share													$ 0.04		$ 0.01					$ 0.05
Inventory Write-down									76,000,000									76,000,000		76,000,000
Inventory Write-down, Effect on Net Income									49,000,000											49,000,000
Inventory Write-down, Amount Per Share									$ 0.05											$ 0.05
Executive Employment Agreement Costs									37,000,000											37,000,000
Executive Employment Agreement Costs, Net of Tax									23,000,000											23,000,000
Executive Employment Agreement Costs, Amount Per Share									$ 0.02											$ 0.02
Income Tax Expense (Benefit) Adjustments									16,000,000				183,000,000					0		199,000,000	[13]	205,000,000	[14],[15]
Income Tax Expense (Benefit) Adjustments, Amount per Share									$ 0.01				$ 0.19							$ 0.20
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain																		0		128,000,000		0
Cerro Verde [Member]
Schedule of Quarterly Financial Information [Line Items]
Charges For New Labor Agreements									36,000,000											36,000,000
Charges For New Labor Agreements Effect On Net Income									13,000,000											13,000,000
Charges For New Labor Agreements Effect on Diluted Earnings Per Share (in dollars per share)									$ 0.01											$ 0.01
Crude Oil and Natural Gas Swaps [Member]
Schedule of Quarterly Financial Information [Line Items]
Unrealized Gain (Loss) on Hedging Instruments	497,000,000		122,000,000		(7,000,000)		15,000,000		(118,000,000)		(158,000,000)		(36,000,000)					627,000,000		(312,000,000)
Unrealized Gain (Loss) on Hedging Instruments, Portion Attributable to Parent	309,000,000		76,000,000		(4,000,000)		9,000,000		(73,000,000)		(98,000,000)		(23,000,000)					389,000,000		(194,000,000)
Unrealized Gain (Loss) on Hedging Instruments, Amount Per Share	$ 0.30		$ 0.07				$ 0.01		$ (0.07)		$ (0.09)		$ (0.02)					$ 0.37		$ (0.19)
McMoRan Exploration Co [Member]
Schedule of Quarterly Financial Information [Line Items]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain					$ 128,000,000								$ 128,000,000							$ 128,000,000
Business Combination, Step Acquisition, Equity Interest In Acquiree Remeasurement Gain, Amount Per Share													$ 0.13							$ 0.13

[1] Includes credits (charges) of $15 million ($9 million to net income attributable to common stockholders or $0.01 per share) in the first quarter, $(7) million ($(4) million to net income attributable to common stockholders) in the second quarter, $122 million ($76 million to net income attributable to common stockholders or $0.07 per share) in the third quarter, $497 million ($309 million to net loss attributable to common stockholders or $0.30 per share) in the fourth quarter and $627 million ($389 million to net loss attributable to common stockholders or $0.37 per share) for the year for net unrealized and noncash realized gains (losses) on crude oil and natural gas derivative contracts.

[2] Includes charges of $36 million ($23 million to net income attributable to common stockholders or $0.02 per share) in the second quarter, $158 million ($98 million to net income attributable to common stockholders or $0.09 per share) in the third quarter, $118 million ($73 million to net income attributable to common stockholders or $0.07 per share) in the fourth quarter and $312 million ($194 million to net income attributable to common stockholders or $0.19 per share) for the year (reflecting the seven-month period from June 1, 2013, to December 31, 2013) for unrealized and noncash realized losses on crude oil and natural gas derivative contracts.

[3] Revenues are attributed to countries based on the location of the customer.

[4] Includes net gains of $46 million ($31 million to net income attributable to common stockholders or $0.03 per share) in third quarter, $671 million ($450 million to net loss attributable to common stockholders or $0.43 per share) in the fourth quarter and $717 million ($481 million to net loss attributable to common stockholders or $0.46 per share) for the year primarily from the sale of the Candelaria and Ojos del Salado copper mining operations in the fourth quarter (refer to Note 2 for further discussion) and the sale of a metals injection molding plant in the third quarter.

[5] Includes a charge of $308 million ($192 million to net income attributable to common stockholders or $0.18 per share) in the third quarter, $3.4 billion ($2.1 billion to net loss attributable to common stockholders or $2.05 per share) in the fourth quarter and $3.7 billion ($2.3 billion to net loss attributable to common stockholders or $2.24 per share) for the year to reduce the carrying value of oil and gas properties pursuant to full cost accounting rules. Additionally, the fourth quarter and the year includes a goodwill impairment charge of $1.7 billion ($1.65 per share) for the full carrying value of goodwill.

[6] Includes charges of $14 million ($10 million to net income attributable to common stockholders or $0.01 per share) in the first quarter, $61 million ($36 million to net income attributable to common stockholders or $0.04 per share) in the second quarter, $1 million ($1 million to net income attributable to common stockholders) in the third quarter, $4 million ($3 million to net income attributable to common stockholders) in the fourth quarter and $80 million ($50 million to net income attributable to common stockholders or $0.05 per share) for the year for transaction and related costs principally associated with the acquisitions of PXP and MMR.

[7] Includes charges in the fourth quarter and for the year of (i) $76 million ($49 million to net income attributable to common stockholders or $0.05 per share) associated with updated mine plans at Morenci that resulted in a loss in recoverable copper in leach stockpiles, (ii) $37 million ($23 million to net income attributable to common stockholders or $0.02 per share) associated with the restructuring of an executive employment arrangement and (iii) $36 million ($13 million to net income attributable to common stockholders or $0.01 per share) associated with a new labor agreement at Cerro Verde.

[8] Includes a tax charge of $57 million ($0.06 per share) in the second quarter, $5 million in the third quarter, $22 million ($0.02 per share) in the fourth quarter and $84 million ($0.08 per share) for the year associated with deferred taxes recorded in connection with the allocation of goodwill to the sale of the Eagle Ford properties. Additionally, includes a net tax charge (benefit) of $54 million ($7 million attributable to noncontrolling interests and $47 million to net income attributable to common stockholders or $0.04 per share) in the third quarter, $(17) million ($11 million attributable to noncontrolling interests and $(28) million to net loss attributable to common stockholders or $(0.03) per share) in the fourth quarter and $37 million ($18 million attributable to noncontrolling interests and $19 million to net loss attributable to common stockholders or $0.02 per share) for the year associated with changes in Chilean tax rules, U.S. federal income tax regulations and Peruvian tax rules, partially offset by a tax benefit related to changes in U.S. state income tax filing positions.

[9] Includes net gains (losses) on early extinguishment of debt totaling $4 million in the second quarter, $17 million ($0.02 per share) in the third quarter, $(18) million ($(0.02) per share) in the fourth quarter and $3 million for the year. Refer to Note 8 for further discussion.

[10] Includes a net tax benefit of $183 million ($0.19 per share) in the second quarter, $16 million ($0.01 per share) in the fourth quarter and $199 million ($0.20 per share) for the year associated with net reductions in FCX's deferred tax liabilities and deferred tax asset valuation allowances related to the acquisitions of PXP and MMR.

[11] Includes net (losses) gains on early extinguishment of debt totaling $(40) million ($(0.04) per share) in the first quarter, $5 million ($0.01 per share) in the second quarter for an adjustment related to taxes on the first quarter losses, $7 million ($0.01 per share) in the fourth quarter and $(28) million ($(0.03) per share) for the year. Refer to Note 8 for further discussion.

[12] Includes a gain of $128 million ($0.13 per share) in the second quarter and for the year related to FCX's preferred stock investment in and the subsequent acquisition of MMR. Refer to Note 2 for further discussion.

[13] As a result of the oil and gas acquisitions, FCX recognized a net tax benefit of $199 million consisting of income tax benefits of $190 million associated with net reductions in FCX's valuation allowances, $69 million related to the release of the deferred tax liability on PXP's investment in MMR common stock and $16 million associated with the revaluation of state deferred tax liabilities, partially offset by income tax expense of $76 million associated with the write off of deferred tax assets related to environmental liabilities.

[14] Cerro Verde previously recorded deferred Peruvian income tax liabilities for income taxes that would become payable if the reinvested profits used to fund the initial Cerro Verde sulfide expansion were distributed prior to the expiration of Cerro Verde's 1998 stability agreement on December 31, 2013. Because reinvested profits at Cerro Verde were not expected to be distributed prior to December 31, 2013, a net deferred income tax liability of $234 million was reversed and recognized as an income tax benefit in 2012.

[15] In 2012, Cerro Verde signed a new 15-year mining stability agreement with the Peruvian government, which became effective January 1, 2014. In connection with the new mining stability agreement, Cerro Verde's income tax rate increased from 30 percent to 32 percent, and FCX recognized additional deferred tax expense of $29 million.