Earnings Per Share (Unaudited) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Earnings Per Share [Abstract]
Net income	$ 1,294		$ 1,533		$ 4,881		$ 3,580
Net income attributable to noncontrolling interests	(241)		(355)		(961)		(793)
Preferred dividends	0		0		0		(63)
Net income attributable to FCX common stockholders	1,053		1,178		3,920		2,724
Plus income impact of assumed conversion of 6.75% Mandatory Convertible Preferred Stock	0	[1]	0	[1]	0	[1]	63	[1]
Diluted net income attributable to FCX common stockholders	$ 1,053		$ 1,178		$ 3,920		$ 2,787
Weighted-average shares of common stock outstanding	948		941		947		906
Add stock issuable upon conversion, exercise or vesting of:
6.75% Mandatory Convertible Preferred Stock (in shares)	0	[1]	0	[1]	0	[1]	34	[1]
Dilutive stock options (in shares)	6	[2]	4	[2]	7	[2]	5	[2]
Restricted stock (in shares)	1		2		1		2
Weighted-average shares of common stock outstanding for purposes of calculating diluted net income per share (in shares)	955		947		955		947
Diluted net income per share attributable to FCX common stockholders (in dollars per share)	$ 1.10		$ 1.24		$ 4.10		$ 2.94
Mandatory convertible preferred stock dividend rate percentage					6.75%
Potential anti-dilutive additional shares of common stock (in shares)	3		0		2		2
Outstanding stock options with exercise prices greater than average market price of common stock	5		19		3		14
Weighted-average exercise price of outstanding stock options not in-the-money	$ 55.57		$ 37.78		$ 55.74		$ 38.32

[1] All outstanding 6¾% Mandatory Convertible Preferred Stock automatically converted on May 1, 2010, into FCX common stock.

[2] Potential additional shares of common stock that were anti-dilutive totaled approximately three million for the three months ended September 30, 2011, none for the three months ended September 30, 2010, and two million for the nine months ended September 30, 2011 and 2010.