Acquisitions (Unaudited) (Details) (USD $)	3 Months Ended		9 Months Ended				1 Months Ended		9 Months Ended	1 Months Ended		3 Months Ended	9 Months Ended	12 Months Ended			3 Months Ended			1 Months Ended	3 Months Ended		3 Months Ended	9 Months Ended				3 Months Ended			9 Months Ended					9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Jun. 03, 2013		May 31, 2013 Plains Exploration & Production Company [Member]		Sep. 30, 2013 Plains Exploration & Production Company [Member]	Jun. 30, 2013 McMoRan Exploration Co [Member]	May 31, 2013 McMoRan Exploration Co [Member]	Sep. 30, 2013 McMoRan Exploration Co [Member]	Sep. 30, 2013 McMoRan Exploration Co [Member]	Dec. 31, 2012 McMoRan Exploration Co [Member]	Jun. 03, 2013 McMoRan Exploration Co [Member]		Sep. 30, 2013 Kokkola Cobalt Chemicals Refinery [Member]	Mar. 31, 2013 Kokkola Cobalt Chemicals Refinery [Member]	Mar. 29, 2013 Kokkola Cobalt Chemicals Refinery [Member]	Feb. 28, 2012 Senior Notes [Member]	Mar. 31, 2013 Senior Notes [Member]	Mar. 07, 2013 Senior Notes [Member]	Sep. 30, 2013 Bank Term Loan [Member]	Sep. 30, 2013 Bank Term Loan [Member]	Feb. 14, 2013 Bank Term Loan [Member]	Mar. 29, 2013 Lundin Mining Corporation [Member] Kokkola Cobalt Chemicals Refinery [Member]	Mar. 29, 2013 La Generale des Carrieres et des Mines [Member] Kokkola Cobalt Chemicals Refinery [Member]	Sep. 30, 2013 Oil & Gas Operations [Member]		Sep. 30, 2012 Oil & Gas Operations [Member]	Sep. 30, 2013 Oil & Gas Operations [Member]		Sep. 30, 2012 Oil & Gas Operations [Member]	Jun. 03, 2013 Common Stock [Member] McMoRan Exploration Co [Member]		Sep. 30, 2013 5.75% Convertible Perpetual Preferred Stock, Series 1 [Member]	Jun. 03, 2013 5.75% Convertible Perpetual Preferred Stock, Series 2 [Member] McMoRan Exploration Co [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition									May 31, 2013				Jun. 03, 2013				Mar. 29, 2013
Debt Instrument, Face Amount																						$ 6,500,000,000			$ 4,000,000,000
Proceeds from Issuance of Long-term Debt																				2,970,000,000	6,400,000,000			4,000,000,000
Term of Debt Agreement																							5 years
Business Acquisition, Agreed-Upon Cost of Entity Acquired, Cash Paid Per Share							$ 25.00								$ 14.75
Payment to Acquire Businesses, Per Share Consideration, Total							3,300,000,000
Payment to Acquire Businesses, Consideration for Equity Awards							7,000,000
Payments of Dividends							411,000,000
Common Stock, Dividends, Per Share, Declared	$ 0.3125	$ 0.3125	$ 1.9375	$ 0.9375			$ 3
Dividends Payable, Date to be Paid							May 31, 2013
Number of shares of common stock acquired							132,280,000	[1]																										112,362,000.000	[2]
Exchange ratio of FCX common stock for each acquiree share							0.6531
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Excluding Shares Related to Stock-based Awards							86,392,000
Shares of FCX common stock issued for equity awards							4,769,000
Total shares of FCX common stock issued							91,161,000
Closing share price of common stock							$ 31.05				$ 16.63				$ 16.75
FCX stock consideration							2,831,000,000
Cash consideration							3,725,000,000	[3]		1,657,000,000
Employee stock-based awards							78,000,000			63,000,000
Total purchase price					8,914,000,000		6,634,000,000								3,128,000,000
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
Number Of Shares Of Investee Preferred Stock Purchased											500,000
Preferred Stock, Dividend Rate, Percentage											5.75%																									5.75%
Cost Method Investments											432,000,000
Investment Owned, Balance, Shares											51,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities					0	[4]	848,000,000	[4]			848,000,000				0	[4]																		854,000,000			554,000,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value										1,400,000,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain	0	0	128,000,000	0								128,000,000
Revenues	6,165,000,000	4,417,000,000	15,036,000,000	13,497,000,000																								1,176,000,000	[5]	0	1,512,000,000	[5],[6]	0
Operating income (loss)	1,707,000,000	1,411,000,000	3,701,000,000	4,456,000,000																								274,000,000		0	338,000,000		0
Business Combination, Acquisition Related Costs	519,000,000																														76,000,000
Deferred Finance Costs, Noncurrent, Net	96,000,000		96,000,000
Investment Owned, Percent of Net Assets																			56.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners																										24.00%	20.00%
Business Combination, Consideration Transferred																		382,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid							3,800,000,000			1,720,000,000								34,000,000
Business Acquisition, Cash Consideration Funding Percentage																			70.00%							30.00%
Business Acquisition, Contingent Consideration, Potential Cash Payment																			$ 110,000,000
Buisness Acquisition, Term of Contingent Consideration																	3 years

[1] Adjusted for cash paid in lieu of fractional shares.

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

[3] 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.

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

[5] Included net charges of $158 million for unrealized losses on oil and gas derivative contracts that were assumed in connection with FCX's acquisition of PXP. For further discussion, refer to Note 9.

[6] Included net charges of $194 million for unrealized losses on oil and gas derivative contracts that were assumed in connection with FCX's acquisition of PXP. For further discussion, refer to Note 9.