CONTINGENCIES (Asset Retirement Obligations) (Details)		12 Months Ended
		Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)		Dec. 31, 2013 USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year		$ 2,769,000,000	$ 2,328,000,000		$ 1,146,000,000
Liabilities assumed in the acquisitions of PXP and MMR	[1]	0	0		1,028,000,000
Liabilities incurred		98,000,000	430,000,000	[2]	45,000,000
Settlements and revisions to cash flow estimates, net		(66,000,000)	65,000,000		123,000,000
Accretion expense		131,000,000	117,000,000		95,000,000
Dispositions		0	(61,000,000)		0
Spending		(133,000,000)	(99,000,000)		(107,000,000)
Other		(3,000,000)	(11,000,000)		(2,000,000)
Balance at end of year		2,796,000,000	2,769,000,000		2,328,000,000
Less current portion		(172,000,000)	(191,000,000)		(115,000,000)
Long-term portion		2,624,000,000	2,578,000,000		$ 2,213,000,000
Fair Value Assumptions, Inflation Rate					2.50%
Financial Assurance Obligations		994,000,000
New Mexico environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Legally Restricted Funds For Asset Retirement Obligations		169,000,000	$ 168,000,000
Accrued reclamation and closure costs		451,000,000
Arizona environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs		298,000,000
Colorado Environmental And Reclamation Programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs		66,000,000
Chile environmental and reclamation programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs		51,000,000
Peru Environmental and Reclamation Programs [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accrued reclamation and closure costs		106,000,000
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		$ 674,000,000
Estimated years the mining activities are expected to continue (in years)		25 years
Current cash balance of reclamation fund		$ 21,000,000
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]
Liabilities incurred		79,000,000
Long-term portion		$ 1,100,000,000
Productive Oil Wells, Number of Wells, Gross		6,400
Asset Retirement Obligations, Number of Platforms		180
Guarantees [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Financial Assurance Obligations		$ 617,000,000
Guarantees [Member] | Freeport-McMoRan Oil & Gas [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Financial Assurance Obligations		$ 1,500,000,000

[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 updates to the closure approach to reclaim an overburden stockpile in Indonesia.