CONTINGENCIES (Asset Retirement Obligations) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year	$ 2,328,000,000		$ 1,146,000,000		$ 921,000,000
Liabilities assumed in the acquisitions of PXP and MMR	0	[1]	1,028,000,000	[1]	0	[1]
Liabilities incurred	430,000,000	[2]	45,000,000		6,000,000
Settlements and revisions to cash flow estimates, net	65,000,000		123,000,000		211,000,000
Accretion expense	117,000,000		95,000,000		55,000,000
Dispositions	(61,000,000)		0		0
Spending	(99,000,000)		(107,000,000)		(47,000,000)
Other	(11,000,000)		(2,000,000)		0
Balance at end of year	2,769,000,000		2,328,000,000		1,146,000,000
Less current portion	(191,000,000)		(115,000,000)		(55,000,000)
Long-term portion	2,578,000,000		2,213,000,000		1,091,000,000
Fair Value Assumptions, Inflation Rate			2.50%
Financial Assurance Obligations Associated With Closure And Reclamation Costs	1,000,000,000
Financial Assurance Obligations Associated With Closure And Reclamation Costs In Form Of Parent Company Guarantees And Financial Capability Demonstrations	636,000,000
Legally Restricted Funds For Asset Retirement Obligations			158,000,000
Productive Oil Wells, Number of Wells, Gross	6,500
Asset Retirement Obligations, Number of Platforms	180
New Mexico environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Legally Restricted Funds For Asset Retirement Obligations	168,000,000
Accrued reclamation and closure costs	450,000,000
Arizona environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs	285,000,000
Colorado Environmental And Reclamation Programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs	73,000,000
Chile environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs	67,000,000
Peru Environmental and Reclamation Programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs	78,000,000
PT Freeport Indonesia environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities incurred	403,000,000
Accrued reclamation and closure costs	636,000,000
Estimated years the mining activities are expected to continue (in years)	25 years
Current cash balance of reclamation fund	20,000,000
Minimum [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Fair Value Assumptions, Risk Free Interest Rate			1.30%
Minimum [Member] | PT Freeport Indonesia environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Current cash balance of reclamation fund	100,000,000
Maximum [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Fair Value Assumptions, Risk Free Interest Rate			6.30%
Plains Exploration & Production Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities assumed in the acquisitions of PXP and MMR			741,000,000
McMoRan Exploration Co [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Liabilities assumed in the acquisitions of PXP and MMR			287,000,000
Freeport-McMoRan Oil & Gas [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Long-term portion	$ 1,100,000,000

[1] The fair value of AROs assumed in the acquisitions of PXP and MMR ($741 million and $287 million, respectively) were estimated based on projected cash flows, an estimated long-term annual inflation rate of 2.5 percent, and discount rates based on FCX's estimated credit-adjusted, risk-free interest rates ranging from 1.3 percent to 6.3 percent.

[2] Primarily reflects revisions to the closure approach to reclaim an overburden stockpile in Indonesia.