Financial Instruments (Unaudited) Oil and Gas (Details) MMBTU in Millions, $ in Millions		9 Months Ended
		Sep. 30, 2015 USD ($) MBbls MMBTU $ / bbl	Dec. 31, 2014 USD ($)
Derivative [Line Items]
Derivative Liability | $		$ 74	$ 99
Maximum Price Limit per Barrel		20
2015 Positions [Member] | Derivatives not designated as hedging instruments [Member] | Crude Oil Options [Member]
Derivative [Line Items]
Daily Volumes (Bbls) | MMBTU		7.7
2015 Positions [Member] | Derivatives not designated as hedging instruments [Member] | Crude Oil Options [Member] | 84 MBbls [Member]
Derivative [Line Items]
Daily Volumes (Bbls) | MBbls	[1]	84
Derivative, Average Floor Price	[1],[2]	90
Derivative, Average Floor Price Limit	[1],[2]	70
Derivative, Underlying Basis	[1]	Brent
Deferred Option Premiums and Accrued Interest [Member]
Derivative [Line Items]
Derivative Liability | $		$ 53	$ 210
Weighted Average [Member] | Crude Oil Options [Member]
Derivative [Line Items]
Deferred Premium Price		6.89
Weighted Average [Member] | 2015 Positions [Member] | Derivatives not designated as hedging instruments [Member] | Crude Oil Options [Member] | 84 MBbls [Member]
Derivative [Line Items]
Deferred Premium Price	[1]	6.89

[1] 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.

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