GUARANTOR FINANCIAL STATEMENTS (Condensed Consolidating Comprehensive (Loss) Income Statement) (Details) (USD $) In Millions, unless otherwise specified	3 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, 2014		Dec. 31, 2013		Dec. 31, 2012
Condensed Comprehensive (Loss) Income Statements [Line Items]
Revenues	$ 5,235	[1]	$ 5,696	[1]	$ 5,522	[1]	$ 4,985	[1]	$ 5,885	[2]	$ 6,165	[2]	$ 4,288	[2]	$ 4,583		$ 21,438	[1],[3]	$ 20,921	[2],[3]	$ 18,010	[3]
Total costs and expenses																	21,341		15,570		12,196
Operating income	(3,299)	[4],[5]	1,132	[4],[5]	1,153		1,111		1,650	[6],[7]	1,707	[6]	639	[6]	1,355	[6]	97	[4],[5]	5,351	[6],[7]	5,814
Interest expense, net																	(630)		(518)		(186)
Net gain (loss) on early extinguishment of debt																	73		(35)		(168)
Gain on investment in McMoRan Exploration Co. (MMR)																	0		128		0
Other income (expense), net																	36		(13)
(Loss) income before income taxes and equity in affiliated companies' net earnings (losses)																	(424)		4,913		5,487
Benefit from (provision for) income taxes																	(324)	[8],[9]	(1,475)	[10]	(1,510)	[11]
Equity in affiliated companies’ net earnings (losses)																	3		3		3
Net (loss) income	(2,735)	[12],[13]	704	[12],[13]	660	[12],[13]	626		959	[14]	1,048		610	[14]	824		(745)	[12],[13]	3,441	[14]	3,980
Net income and preferred dividends attributable to noncontrolling interests	(117)		(152)		(178)		(116)		(252)		(227)		(128)		(176)		(563)		(783)
Net (loss) income attributable to FCX common stockholders	(2,852)	[1],[12],[13],[4],[5]	552	[1],[12],[13],[4],[5]	482	[1],[12],[13]	510	[1]	707	[14],[15],[2],[6],[7]	821	[2],[6]	482	[14],[15],[16],[2],[6]	648	[15],[6]	(1,308)	[1],[12],[13],[4],[5]	2,658	[14],[15],[16],[2],[6],[7]	3,041
Other comprehensive income																	(139)		101
Total comprehensive income (loss)																	(1,447)		2,759		3,000
Impairment of oil and gas properties and goodwill																	5,454
FCX Issuer [Member]
Condensed Comprehensive (Loss) Income Statements [Line Items]
Revenues																	0		0
Total costs and expenses																	59		134
Operating income																	(59)		(134)
Interest expense, net																	(382)		(319)
Net gain (loss) on early extinguishment of debt																	(5)		(45)
Gain on investment in McMoRan Exploration Co. (MMR)																			128
Other income (expense), net																	72		61
(Loss) income before income taxes and equity in affiliated companies' net earnings (losses)																	(374)		(309)
Benefit from (provision for) income taxes																	73		81
Equity in affiliated companies’ net earnings (losses)																	(1,007)		2,886
Net (loss) income																	(1,308)		2,658
Net income and preferred dividends attributable to noncontrolling interests																	0		0
Net (loss) income attributable to FCX common stockholders																	(1,308)		2,658
Other comprehensive income																	0		0
Total comprehensive income (loss)																	(1,308)		2,658
Impairment of oil and gas properties and goodwill																	0
FM O&G LLC Guarantor [Member]
Condensed Comprehensive (Loss) Income Statements [Line Items]
Revenues																	2,356		1,177
Total costs and expenses																	3,498	[17]	1,065
Operating income																	(1,142)		112
Interest expense, net																	(139)		(129)
Net gain (loss) on early extinguishment of debt																	78		0
Gain on investment in McMoRan Exploration Co. (MMR)																			0
Other income (expense), net																	3		0
(Loss) income before income taxes and equity in affiliated companies' net earnings (losses)																	(1,200)		(17)
Benefit from (provision for) income taxes																	281		17
Equity in affiliated companies’ net earnings (losses)																	(3,429)		281
Net (loss) income																	(4,348)		281
Net income and preferred dividends attributable to noncontrolling interests																	0		0
Net (loss) income attributable to FCX common stockholders																	(4,348)		281
Other comprehensive income																	0		0
Total comprehensive income (loss)																	(4,348)		281
Impairment of oil and gas properties and goodwill																	1,922
Non-Guarantor Subsidiaries [Member]
Condensed Comprehensive (Loss) Income Statements [Line Items]
Revenues																	19,082		19,744
Total costs and expenses																	17,762	[17]	14,371
Operating income																	1,320		5,373
Interest expense, net																	(189)		(129)
Net gain (loss) on early extinguishment of debt																	0		10
Gain on investment in McMoRan Exploration Co. (MMR)																			0
Other income (expense), net																	41		(15)
(Loss) income before income taxes and equity in affiliated companies' net earnings (losses)																	1,172		5,239
Benefit from (provision for) income taxes																	(686)		(1,573)
Equity in affiliated companies’ net earnings (losses)																	(4,633)		268
Net (loss) income																	(4,147)		3,934
Net income and preferred dividends attributable to noncontrolling interests																	(519)		(706)
Net (loss) income attributable to FCX common stockholders																	(4,666)		3,228
Other comprehensive income																	(139)		101
Total comprehensive income (loss)																	(4,805)		3,329
Impairment of oil and gas properties and goodwill																	3,486
Eliminations [Member]
Condensed Comprehensive (Loss) Income Statements [Line Items]
Revenues																	0		0
Total costs and expenses																	22		0
Operating income																	(22)		0
Interest expense, net																	80		59
Net gain (loss) on early extinguishment of debt																	0		0
Gain on investment in McMoRan Exploration Co. (MMR)																			0
Other income (expense), net																	(80)		(59)
(Loss) income before income taxes and equity in affiliated companies' net earnings (losses)																	(22)		0
Benefit from (provision for) income taxes																	8		0
Equity in affiliated companies’ net earnings (losses)																	9,072		(3,432)
Net (loss) income																	9,058		(3,432)
Net income and preferred dividends attributable to noncontrolling interests																	(44)		(77)
Net (loss) income attributable to FCX common stockholders																	9,014		(3,509)
Other comprehensive income																	0		0
Total comprehensive income (loss)																	9,014		(3,509)
Impairment of oil and gas properties and goodwill																	$ 46

[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 charges related to changes in Chilean and Peruvian tax rules of $54 million and $24 million, respectively.

[9] Includes a net charge of $221 million related to the sale of Candelaria/Ojos.

[10] Includes a net tax benefit of $199 million as a result of the oil and gas acquisitions.

[11] Includes the reversal of Cerro Verde's deferred income tax liability of $234 million.

[12] 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.

[13] 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.

[14] 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.

[15] 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.

[16] 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.

[17] Includes impairment charges totaling $1.9 billion at the FM O&G LLC Guarantor and $3.5 billion at the non-guarantor subsidiaries related to ceiling test impairment charges for FCX's oil and gas properties pursuant to full cost accounting rules and a goodwill impairment charge.