DISPOSITIONS AND ACQUISITIONS (Details)		1 Months Ended		3 Months Ended																		6 Months Ended		12 Months Ended
		Jun. 30, 2013 USD ($)	May. 31, 2013 USD ($) $ / shares shares	Dec. 31, 2015 USD ($)		Sep. 30, 2015 USD ($)		Jun. 30, 2015 USD ($)		Mar. 31, 2015 USD ($)		Dec. 31, 2014 USD ($)		Sep. 30, 2014 USD ($)		Jun. 30, 2014 USD ($)		Mar. 31, 2014 USD ($)		Dec. 31, 2013 USD ($)	Mar. 31, 2013 USD ($)	Jun. 30, 2014 USD ($)		Dec. 31, 2015 USD ($) $ / shares		Dec. 31, 2014 USD ($) $ / shares		Dec. 31, 2013 USD ($) $ / shares		Dec. 31, 2012 USD ($)	Sep. 08, 2014 USD ($)	Jun. 20, 2014 USD ($)	Jun. 03, 2013 USD ($) $ / shares shares	Mar. 29, 2013 USD ($)	Mar. 07, 2013 USD ($)	Feb. 14, 2013 USD ($)
Business Acquisition [Line Items]
Payments of Dividends																								$ 725,000,000		$ 1,729,000,000		$ 2,537,000,000
Common Stock, Dividends, Per Share, Declared | $ / shares																								$ 0.2605		$ 1.25		$ 2.25
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net																$ 8,919,000,000						$ 8,919,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities	[1]															0						0
Payments for Repurchase of Preferred Stock and Preference Stock																								$ 0		$ 0		$ 228,000,000
Royalty Trust Units Issued, Conversion of Debt or Equity Instrument																												17,700,000
Gain on investment in McMoRan Exploration Co. (MMR)																								0		0		$ 128,000,000
Revenues				$ 3,795,000,000	[2]	$ 3,681,000,000	[2]	$ 4,248,000,000	[2]	$ 4,153,000,000	[2]	$ 5,235,000,000	[3]	$ 5,696,000,000	[3]	5,522,000,000	[3]	$ 4,985,000,000	[3]					15,877,000,000	[2],[4]	21,438,000,000	[3],[4]	20,921,000,000	[4]
Operating income				(4,100,000,000)	[5],[6],[7]	(3,945,000,000)	[5],[6],[7]	(2,374,000,000)	[5],[6],[7]	(2,963,000,000)	[5],[6],[7]	(3,299,000,000)	[8],[9]	1,132,000,000	[8],[9]	1,153,000,000		$ 1,111,000,000						(13,382,000,000)	[5],[6],[7]	97,000,000	[8],[9]	5,351,000,000
Income Tax Expense (Benefit), Changes in Deferred Tax Liabilities and Deferred Tax Asset Valuation Allowances				1,400,000,000		$ 1,100,000,000		$ 305,000,000		$ 458,000,000		$ 22,000,000		$ 5,000,000		57,000,000								3,300,000,000		84,000,000		190,000,000
Gain (Loss) on Disposition of Oil and Gas Property																												$ 77,000,000
8% Convertible Perpetual Preferred Stock [Member]
Business Acquisition [Line Items]
Preferred Stock, Dividend Rate, Percentage																												8.00%
5.75% Convertible Perpetual Preferred Stock, Series 1 [Member]
Business Acquisition [Line Items]
Preferred Stock, Dividend Rate, Percentage																												5.75%
Deepwater Gulf of Mexico Interests [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Asset Retirement Costs																						$ 10,000,000
Business Acquisition, Effective Date of Acquisition														Sep. 08, 2014								Jun. 30, 2014
Business Combination, Consideration Transferred														$ 496,000,000								$ 918,000,000
Business Combination, Adjustment to Recognized Identifiable Assets Acquired and Liabilities Assumed Oil and Gas Properties Subject to Depletion														$ 509,000,000								451,000,000
Business Combination, Adjustment to Recognized Identifiable Assets Acquired and Liabilities Assumed Oil and Gas Properties Not Subject to Depletion																						$ 477,000,000
Eagle Ford [Member]
Business Acquisition [Line Items]
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
Business Combination, Consideration Transferred																						$ 3,100,000,000
Deposits																															$ 414,000,000	$ 1,300,000,000
Plains Exploration & Production Company [Member]
Business Acquisition [Line Items]
Dividends Payable, Date to be Paid			May 31, 2013
Business Acquisition, Effective Date of Acquisition			May 31, 2013																									May 31, 2013
Business Acquisition, Agreed-Upon Equity Interest Issued or Issuable, Number of Shares Per Share of Target Company | shares			0.6531
Business Acquisitions, Agreed-Upon Cost of Entity Acquired, Cash Paid Per Share | $ / shares			$ 25.00
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares			91,161,000
Payments to Acquire Businesses, Gross			$ 3,800,000,000
Payments of Dividends			$ 411,000,000
Common Stock, Dividends, Per Share, Declared | $ / shares			$ 3
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net			$ 6,639,000,000													6,639,000,000						6,639,000,000
Common Stock, Shares, Outstanding | shares			132,280,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Excluding Shares Related to Employee Stock-based Awards | shares			86,392,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Related to Employee Stock-based Awards | shares			4,769,000
Share Price | $ / shares			$ 31.05
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable			$ 2,831,000,000
Payment to Acquire Businesses, Excluding Payments for Employee Stock-based Awards	[10]		3,725,000,000
Other Payments to Acquire Businesses			83,000,000
Payment to Acquire Businesses, Per Share Consideration, Total			3,300,000,000
Payment to Acquire Businesses, Consideration for Equity Awards			$ 7,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities	[1]															848,000,000						848,000,000
Deferred Finance Costs, Noncurrent, Net																				$ 96,000,000								$ 96,000,000
McMoRan Exploration Co [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition																												Jun. 03, 2013
Business Acquisitions, Agreed-Upon Cost of Entity Acquired, Cash Paid Per Share | $ / shares																																	$ 14.75
Payments to Acquire Businesses, Gross		$ 1,720,000,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net																3,128,000,000						3,128,000,000											$ 3,128,000,000
Share Price | $ / shares			$ 16.63																														$ 16.75
Payment to Acquire Businesses, Excluding Payments for Employee Stock-based Awards		1,657,000,000
Other Payments to Acquire Businesses		$ 63,000,000
Buinsess Acquisition, Agreed-Upon Royalty Trust Units Issued or Issuable, Per Share of Target Company		1.15
Royalty Interest in Future Production																																	5.00%
Business Acquisition, Date of Acquisition Agreement																														Dec. 05, 2012
Investment Owned, Balance, Shares | shares			51,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities			$ 848,000,000													0	[1]					0	[1]
Number Of Shares Of Investee Preferred Stock Purchased | shares			500,000
Preferred Stock, Dividend Rate, Percentage			5.75%
Cost-method investment			$ 432,000,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value		$ 1,400,000,000
Gain on investment in McMoRan Exploration Co. (MMR)																128,000,000
McMoRan Exploration Co [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Common Stock, Shares, Outstanding | shares	[11]																																112,362,000.000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities																																	$ 854,000,000
McMoRan Exploration Co [Member] | 5.75% Convertible Perpetual Preferred Stock, Series 2 [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities																																	$ 554,000,000
Kokkola Cobalt Chemicals Refinery [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition																					Mar. 29, 2013
Payments to Acquire Businesses, Gross																					$ 34,000,000
Company's direct ownership percentage																																		56.00%
Business Combination, Consideration Transferred																					$ 382,000,000
Business Acquisition, Cash Consideration Funding Percentage																																		70.00%
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High																																		$ 110,000,000
Buisness Combination, Term of Contingent Consideration																												3 years
Intersubsegment Eliminations [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net																(848,000,000)						(848,000,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities	[1]															$ (848,000,000)						$ (848,000,000)
Senior Notes [Member]
Business Acquisition [Line Items]
Debt Instrument, Face Amount																																			$ 6,500,000,000
Proceeds from Issuance of Long-term Debt																										2,970,000,000		$ 6,400,000,000		$ 2,470,000,000
Bank Term Loan [Member]
Business Acquisition [Line Items]
Debt Instrument, Face Amount				$ 4,000,000,000																				4,000,000,000												$ 4,000,000,000
Term of Debt Agreement																				5 years
Oil and Gas Operations Segment [Member]
Business Acquisition [Line Items]
Revenues																								1,994,000,000	[12],[13]	4,710,000,000	[12],[13]	2,616,000,000	[14]
Operating income																								$ (14,189,000,000)	[13]	$ (4,479,000,000)	[13]	450,000,000
Business Combination, Acquisition Related Costs																												$ 74,000,000
Lundin Mining Corporation [Member] | Kokkola Cobalt Chemicals Refinery [Member]
Business Acquisition [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners																																		24.00%
Business Acquisition, Cash Consideration Funding Percentage																																		30.00%
La Generale des Carrieres et des Mines [Member] | Kokkola Cobalt Chemicals Refinery [Member]
Business Acquisition [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners																																		20.00%

[1] PXP owned 51 million shares of MMR common stock, which were eliminated in FCX's consolidated balance sheet at the acquisition date of MMR.

[2] Includes charges of $48 million ($30 million to net loss attributable to common stockholders or $0.03 per share) in the first quarter, $95 million ($59 million to net loss attributable to common stockholders or $0.06 per share) in the second quarter, $74 million ($46 million to net loss attributable to common stockholders or $0.04 per share) in the third quarter, $102 million ($63 million to net loss attributable to common stockholders or $0.05 per share) in the fourth quarter and $319 million ($198 million to net loss attributable to common stockholders or $0.18 per share) for the year for net noncash mark-to-market losses on crude oil derivative contracts.

[3] 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 noncash mark-to-market gains (losses) on crude oil and natural gas derivative contracts.

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

[5] Includes charges at oil and gas operations of $17 million ($10 million to net loss attributable to common stockholders or $0.01 per share) in the first quarter, $22 million ($14 million to net loss attributable to common stockholders or $0.01 per share) in the second quarter, $21 million ($13 million to net loss attributable to common stockholders or $0.01 per share) in the third quarter, $129 million ($81 million to net loss attributable to common stockholders or $0.07 per share) in the fourth quarter and $188 million ($117 million to net loss attributable to common stockholders or $0.11 per share) for the year for other asset impairments and inventory write-downs, idle/terminated rig costs and prior year non-income tax assessments related to the California properties.

[6] Includes charges of $3.1 billion ($2.4 billion to net loss attributable to common stockholders or $2.31 per share) in the first quarter, $2.7 billion ($2.0 billion to net loss attributable to common stockholders or $1.90 per share) in the second quarter, $3.7 billion ($3.5 billion to net loss attributable to common stockholders or $3.25 per share) in the third quarter, $3.7 billion ($3.7 billion to net loss attributable to common stockholders or $3.18 per share) in the fourth quarter and $13.1 billion ($11.6 billion to net loss attributable to common stockholders or $10.72 per share) for the year to reduce the carrying value of oil and gas properties pursuant to full cost accounting rules. Additionally, after-tax impacts to net loss include net tax charges of $458 million ($0.44 per share) in the first quarter, $305 million ($0.29 per share) in the second quarter, $1.1 billion ($1.07 per share) in the third quarter, $1.4 billion ($1.21 per share) in the fourth quarter and $3.3 billion ($3.09 per share) for the year to establish a valuation allowance primarily against U.S. federal alternative minimum tax credits and foreign tax credits, partly offset by a tax benefit related to the impairment of the Morocco oil and gas properties in the third quarter.

[7] Includes charges of $4 million ($3 million to net loss attributable to common stockholders) in the first quarter, $59 million ($38 million to net loss attributable to common stockholders or $0.04 per share) in the second quarter, $91 million ($58 million to net loss attributable to common stockholders or $0.05 per share) in the third quarter, $184 million ($118 million to net loss attributable to common stockholders or $0.10 per share) in the fourth quarter and $338 million ($217 million to net loss attributable to common stockholders or $0.20 per share) for the year associated with inventory adjustments to copper and molybdenum inventories. Additionally, includes charges at mining operations of $95 million ($58 million to net loss attributable to common stockholders or $0.05 per share) in the third quarter, $64 million ($38 million to net loss attributable to common stockholders or $0.03 per share) in the fourth quarter and $156 million ($94 million to net loss attributable to common stockholders or $0.09 per share) for the year associated with impairments, restructuring and other net charges.

[8] Includes charges 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, includes charges at the oil and gas operations in the fourth quarter and for the year of (i) $1.7 billion ($1.7 billion to net loss attributable to common stockholders or $1.65 per share) for the impairment of the full carrying value of goodwill and (ii) $46 million ($29 million to net loss attributable to common stockholders or $0.03 per share) for idle/terminated rig costs and inventory write-downs.

[9] Includes net gains of $46 million ($31 million to net income attributable to common stockholders or $0.03 per share) in the 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.

[10] Cash consideration includes the payment of $25.00 in cash for each PXP share ($3.3 billion), cash paid in lieu of any fractional shares of FCX common stock, cash paid for certain equity awards ($7 million) and the value of the $3 per share PXP special cash dividend ($411 million) paid on May 31, 2013.

[11] Excludes 51 million shares of MMR common stock owned by FCX through its acquisition of PXP on May 31, 2013.

[12] Includes net mark-to-market gains associated with crude oil and natural gas derivative contracts totaling $87 million in 2015 and $505 million in 2014.

[13] Includes the results of Eagle Ford prior to its sale in June 2014.

[14] Includes net mark-to-market losses associated with crude oil and natural gas derivative contracts totaling $334 million for the period from June 1, 2013, to December 31, 2013