Financial Instruments (Unaudited) Oil and Gas (Details) (USD $) In Millions, unless otherwise specified					6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Derivatives not designated as hedging instruments [Member] Crude Oil Swaps [Member] MMBbls	Jun. 30, 2013 Derivatives not designated as hedging instruments [Member] Natural gas swaps [Member] MMBTU	Jun. 30, 2013 2013 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Swaps [Member] MBbls		Jun. 30, 2013 2013 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 13 MBbls [Member] Put Option [Member] MBbls		Jun. 30, 2013 2013 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 25 MBbls [Member] Three-way Collars [Member] MBbls		Jun. 30, 2013 2013 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 5 MBbls [Member] Three-way Collars [Member] MBbls		Jun. 30, 2013 2013 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 17 MBbls [Member] Put Option [Member] MBbls		Jun. 30, 2013 2013 Positions [Member] Derivatives not designated as hedging instruments [Member] Natural gas swaps [Member] MMBTU		Jun. 30, 2013 2014 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 5 MBbls [Member] Put Option [Member] MBbls		Jun. 30, 2013 2014 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 30 MBbls [Member] Put Option [Member] MBbls		Jun. 30, 2013 2014 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 75 MBbls [Member] Put Option [Member] MBbls		Jun. 30, 2013 2014 Positions [Member] Derivatives not designated as hedging instruments [Member] Natural gas swaps [Member] MMBTU		Jun. 30, 2013 2015 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 84 MBbls [Member] Put Option [Member] MBbls		Jun. 30, 2013 Deferred Option Premiums and Accrued Interest [Member]	Jun. 30, 2013 Weighted Average [Member] Crude Oil Options [Member]	Jun. 30, 2013 Weighted Average [Member] 2013 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 13 MBbls [Member] Put Option [Member]		Jun. 30, 2013 Weighted Average [Member] 2013 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 17 MBbls [Member] Put Option [Member]		Jun. 30, 2013 Weighted Average [Member] 2014 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 5 MBbls [Member] Put Option [Member]		Jun. 30, 2013 Weighted Average [Member] 2014 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 30 MBbls [Member] Put Option [Member]		Jun. 30, 2013 Weighted Average [Member] 2014 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 75 MBbls [Member] Put Option [Member]		Jun. 30, 2013 Weighted Average [Member] 2015 Positions [Member] Derivatives not designated as hedging instruments [Member] Crude Oil Options [Member] 84 MBbls [Member] Put Option [Member]
Derivative [Line Items]
Derivative Liability	$ 223	$ 20																									$ 478
Daily Volumes (Bbls)			7	57	40	[1]	13	[2]	25	[3]	5	[3]	17	[2]	110,000	[1]	5	[2]	30	[2]	75	[2]	100,000	[1]	84	[2]
Derivative, Average Cap Price									124.29	[3],[4]	126.08	[3],[4]
Derivative, Average Floor Price							100	[2],[4]	100	[3],[4]	90	[3],[4]	90	[2],[4]			100	[2],[4]	95	[2],[4]	90	[2],[4]			90	[2],[4]
Derivative, Average Floor Price Limit							80	[2],[4]	80	[3],[4]	70	[3],[4]	70	[2],[4]			80	[2],[4]	75	[2],[4]	70	[2],[4]			70	[2],[4]
Deferred Premium Price																												6.35	6.80	[2]	6.25	[2]	7.11	[2]	6.09	[2]	5.74	[2]	6.89	[2]
Derivative, Underlying Basis					Brent	[1]	Brent	[2]	Brent	[3]	Brent	[3]	Brent	[2]	Henry Hub	[1]	Brent	[2]	Brent	[2]	Brent	[2]	Henry Hub	[1]	Brent	[2]
Derivative Latest Maturity Period					December 2013	[1]									December 2013	[1]							December 2014	[1]
Maximum Price Limit per Barrel	20
Derivative, Swap Type, Fixed Price			109.23	4.15	109.23	[1]									4.27	[1]							4.09	[1]

[1] If the index price is less than the fixed price, FCX receives the difference between the fixed price and the index price. FCX pays the difference between the index price and the fixed price if the index price is greater than the fixed price.

[2] If the index price is less than the per barrel floor, FCX receives the difference between the per barrel floor and the index price up to a maximum of $20 per barrel less the option premium. If the index price is at or above the per barrel floor, FCX pays the option premium and no cash settlement is received.

[3] If the index price is less than the per barrel floor, FCX receives the difference between the per barrel floor and the index price up to a maximum of $20 per barrel. FCX pays the difference between the index price and the per barrel ceiling if the index price is greater than the per barrel ceiling. If the index price is at or above the per barrel floor and at or below the per barrel ceiling, no cash settlement is required.

[4] The average strike prices do not reflect any premiums to purchase the put options.