Contingencies and Commitments (Unaudited) Asset Retirement Obligations (Details) (USD $)	9 Months Ended
	Sep. 30, 2013
Asset Retirement Obligations Rollforward [Line Items]
Balance at December 31, 2012	$ 1,146,000,000
Liabilities assumed in the acquisitions of PXP and MMR	1,024,000,000	[1]
Liabilities incurred	15,000,000
Settlements and revisions to cash flow estimates, net	(3,000,000)
Accretion expense	66,000,000
Spending	(62,000,000)
Other	(3,000,000)
Balance at September 30, 2013	2,183,000,000
Less: current portion	125,000,000
Long-term portion	2,058,000,000
Fair Value Assumptions, Inflation Rate	2.50%
Plains Exploration & Production Company [Member]
Asset Retirement Obligations Rollforward [Line Items]
Liabilities assumed in the acquisitions of PXP and MMR	741,000,000
McMoRan Exploration Co [Member]
Asset Retirement Obligations Rollforward [Line Items]
Liabilities assumed in the acquisitions of PXP and MMR	$ 283,000,000
Minimum [Member]
Asset Retirement Obligations Rollforward [Line Items]
Fair Value Assumptions, Risk Free Interest Rate	1.30%
Maximum [Member]
Asset Retirement Obligations Rollforward [Line Items]
Fair Value Assumptions, Risk Free Interest Rate	6.30%

[1] The fair value of AROs assumed in the acquisitions of PXP and MMR ($741 million and $283 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.