DISPOSITIONS AND ACQUISITIONS (Dispositions) (Details) (USD $)	3 Months Ended																12 Months Ended					10 Months Ended	6 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	Nov. 03, 2014	Jun. 30, 2014	Oct. 06, 2014	Sep. 08, 2014	Jun. 20, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling interests	$ 4,187,000,000								$ 4,297,000,000								$ 4,187,000,000		$ 4,297,000,000
(Loss) income before income taxes and equity in affiliated companies' net earnings (losses)																	(424,000,000)		4,913,000,000		5,487,000,000
Net income attributable to FCX common stockholders	(2,852,000,000)	[1],[2],[3],[4],[5]	552,000,000	[1],[2],[3],[4],[5]	482,000,000	[1],[3],[5]	510,000,000	[1]	707,000,000	[10],[6],[7],[8],[9]	821,000,000	[8],[9]	482,000,000	[10],[11],[7],[8],[9]	648,000,000	[10],[8]	(1,308,000,000)	[1],[2],[3],[4],[5]	2,658,000,000	[10],[11],[6],[7],[8],[9]	3,041,000,000
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
Candelaria and Ojos del Salado Mining Complex [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date	Nov. 03, 2014
Company's direct ownership percentage																								80.00%
Proceeds from Divestiture of Businesses, Net of Cash Divested	1,800,000,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High																						200,000,000
Business Combination, Contingent Consideration Arrangements, Basis for Amount	five percent of net copper revenues in any annual period over the next five years when the average realized copper price exceeds $4.00 per pound
Proceeds from Divestiture of Businesses, Net of Tax	1,500,000,000
Significant Acquisitions and Disposals, Gain (Loss) on Sale or Disposal, Pretax																						671,000,000
Significant Acquisitions and Disposals, Gain (Loss) on Sale or Disposal, Net of Tax																						450,000,000
Business Acquisition, Effective Date of Acquisition	Jun. 30, 2014
Current assets																						482,000,000
Long-term assets																						1,155,000,000
Current liabilities																						129,000,000
Long-term liabilities																						89,000,000
Noncontrolling interests																						242,000,000
(Loss) income before income taxes and equity in affiliated companies' net earnings (losses)																			689,000,000		547,000,000	270,000,000
Net income attributable to FCX common stockholders																			341,000,000		304,000,000	144,000,000
Eagle Ford [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date																							Jun. 20, 2014
Business Combination, Consideration Transferred																							3,100,000,000
Business Acquisition, Effective Date of Acquisition																							Apr. 01, 2014
Income Tax Expense (Benefit), Changes in Deferred Tax Liabilities and Deferred Tax Asset Valuation Allowances					84,000,000
Adjustment to Goodwill																	(221,000,000)						221,000,000
Deposits																									$ 414,000,000	$ 1,300,000,000

[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 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.

[3] 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.

[4] 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.

[5] 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.

[6] 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.

[7] 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.

[8] 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.

[9] 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.

[10] 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.

[11] 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.