Subsequent Events (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended						1 Months Ended		9 Months Ended	1 Months Ended		3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Jun. 03, 2013	Dec. 31, 2012	Oct. 31, 2013 Subsequent Event [Member] acre	Sep. 30, 2013 5.25% Convertible Senior Notes due 2013 [Member]	Oct. 31, 2013 5.25% Convertible Senior Notes due 2013 [Member] Subsequent Event [Member]	Oct. 31, 2013 Pura Vida Energy [Member] Subsequent Event [Member]	Sep. 30, 2013 Freeport-McMoRan Oil & Gas [Member]	Oct. 31, 2013 Freeport-McMoRan Oil & Gas [Member] Subsequent Event [Member]	Sep. 30, 2013 Senior Notes [Member] McMoRan Exploration Co [Member] 11.875% Senior Notes due 2014 [Member]	Dec. 31, 2013 Senior Notes [Member] McMoRan Exploration Co [Member] 11.875% Senior Notes due 2014 [Member] Subsequent Event [Member]	Oct. 15, 2013 Senior Notes [Member] McMoRan Exploration Co [Member] 11.875% Senior Notes due 2014 [Member] Subsequent Event [Member]	Sep. 30, 2013 Senior Notes [Member] McMoRan Exploration Co [Member] 5.25% Convertible Senior Notes due 2013 [Member]
Subsequent Event [Line Items]
Convertible Debt, Fair Value Disclosures									$ 67
Payments for Repurchase of Preferred Stock and Preference Stock			227	0					(59)
Royalty Trust Units Issued, Conversion of Debt or Equity Instrument									4,600,000
Royalty Trust Units, Fair Value Disclosure					31				8
Long-term Debt, Gross	21,123		21,123			3,527									299
Debt Instrument, Interest Rate, Stated Percentage								5.25%					11.875%		11.875%	5.25%
Debt Instrument, Redemption Date														Nov. 15, 2013
Gains (Losses) on Extinguishment of Debt	0	0	(45)	(168)							0			8
Farm In Drilling Completion Costs							15
Working Interest in Oil and Gas Property										75.00%		52.00%
Percentage Of Agreed Upon Exploration Costs Shared By Joint Venture Partners												100.00%
Exploratory Wells Drilled Commitment							2
Gas and Oil Area, Undeveloped, Gross Acres							2,700,000
Oil And Gas Exploration Working Interest Agreement Fixed Fee Remaining							$ 215