Earnings Per Share (Unaudited) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income	$ 1,140	$ 1,294		$ 3,035		$ 4,881
Net income attributable to noncontrolling interests	(316)	(241)		(737)		(961)
Net income attributable to FCX common stockholders	$ 824	$ 1,053		$ 2,298		$ 3,920
Weighted-average shares of common stock outstanding	949	948		949		947
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Weighted-average shares of common stock outstanding for purposes of calculating diluted net income per share (in shares)	953	955		953		955
Diluted net income per share attributable to FCX common stockholders (in dollars per share)	$ 0.86	$ 1.10		$ 2.41		$ 4.10
Potential anti-dilutive additional shares of common stock (in shares)		3		1		2
Outstanding stock options with exercise prices greater than average market price of common stock	24	5		19		3
Weighted-average exercise price of outstanding stock options not in-the-money	$ 42.52	$ 55.57		$ 43.80		$ 55.74
Dilutive Stock Options [Member]
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Incremental common shares (in shares)	3	6	[1]	3	[1]	7	[1]
Restricted Stock Units [Member]
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Incremental common shares (in shares)	1	1		1		1

[1] Excluded shares of common stock associated with outstanding stock options with exercise prices less than the average market price of FCX's common stock that were anti-dilutive based on the treasury stock method of approximately three million for the third-quarter 2011, one million for the nine months ended September 30, 2012, and two million for the nine months ended September 30, 2011.