CONSOLIDATED STATEMENTS OF EQUITY (USD $) In Millions, unless otherwise specified	Total		Convertible Perpetual Preferred Stock [Member]	Mandatory Convertible Preferred Stock [Member]	Common Stock [Member]	Capital in Excess of Par Value [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Common Stock Held in Treasury [Member]	Total FCX Stockholders' Equity [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2008	$ 7,101		$ 832	$ 2,875	$ 89	$ 13,951	$ (8,267)	$ (305)	$ (3,402)	$ 5,773	$ 1,328
Balance (in shares) at Dec. 31, 2008			1	29	889				121
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversions and redemptions of 5 1/2% Convertible Perpetual Preferred Stock	(1)		(832)		4	827				(1)
Conversions and redemptions of 5 1/2% Convertible Perpetual Preferred Stock (in shares)			(1)		36
Sale of common stock	740				5	735				740
Sale of common stock (in shares)					53
Exercised and issued stock-based awards	18					18				18
Exercised and issued stock-based awards (in shares)					3
Stock-based compensation	100					100				100
Tax benefit for stock-based awards	6					6				6
Tender of shares for stock-based awards	(11)								(11)	(11)
Tender of shares for stock-based awards (in shares)									1
Dividends on common stock	(65)						(65)			(65)
Dividends on preferred stock	(222)						(222)			(222)
Distributions to noncontrolling interests	(535)										(535)
Contributions from noncontrolling interests	59										59
Comprehensive income:
Net income	3,534						2,749			2,749	785
Other comprehensive income (loss), net of taxes:
Unrealized gains (losses) on securities	3							3		3
Translation adjustment	3							3		3
Defined benefit plans:
Net gain (loss) during period, net of taxes	9							8		8	1
Amortization of unrecognized amounts	18							18		18
Other comprehensive income (loss)	33							32		32	1
Total comprehensive income	3,567									2,781	786
Balance at Dec. 31, 2009	10,757		0	2,875	98	15,637	(5,805)	(273)	(3,413)	9,119	1,638
Balance (in shares) at Dec. 31, 2009			0	29	981				122
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversions of 6 3/4% Mandatory Convertible Preferred Stock				(2,875)	8	2,867
Conversions of 6 3/4% Mandatory Convertible Preferred Stock (in shares)				(29)	79
Conversions of 7% Convertible Senior Notes	1					1				1
Exercised and issued stock-based awards	110				1	109				110
Exercised and issued stock-based awards (in shares)					7
Stock-based compensation	129					129				129
Tax benefit for stock-based awards	8					8				8
Tender of shares for stock-based awards	(28)								(28)	(28)
Tender of shares for stock-based awards (in shares)
Dividends on common stock	(1,058)						(1,058)			(1,058)
Dividends on preferred stock	(63)						(63)			(63)
Distributions to noncontrolling interests	(816)										(816)
Contributions from noncontrolling interests	28										28
Comprehensive income:
Net income	5,544						4,336			4,336	1,208
Other comprehensive income (loss), net of taxes:
Unrealized gains (losses) on securities	2							2		2
Defined benefit plans:
Net gain (loss) during period, net of taxes	(69)							(67)		(67)	(2)
Amortization of unrecognized amounts	15							15		15
Other comprehensive income (loss)	(52)							(50)		(50)	(2)
Total comprehensive income	5,492									4,286	1,206
Balance at Dec. 31, 2010	14,560		0	0	107	18,751	(2,590)	(323)	(3,441)	12,504	2,056
Balance (in shares) at Dec. 31, 2010			0	0	1,067				122
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercised and issued stock-based awards	48					48				48
Exercised and issued stock-based awards (in shares)					4
Stock-based compensation	117					117				117
Tax benefit for stock-based awards	24					24				24
Tender of shares for stock-based awards	(45)					67			(112)	(45)
Tender of shares for stock-based awards (in shares)									1
Dividends on common stock	(1,424)						(1,424)			(1,424)
Dividends on preferred stock	0
Distributions to noncontrolling interests	(391)										(391)
Contributions from noncontrolling interests	62										62
Comprehensive income:
Net income	5,747	[1]					4,560			4,560	1,187
Other comprehensive income (loss), net of taxes:
Unrealized gains (losses) on securities	(1)							(1)		(1)
Translation adjustment	(2)							(2)		(2)
Defined benefit plans:
Net gain (loss) during period, net of taxes	(157)							(154)		(154)	(3)
Amortization of unrecognized amounts	15							15		15
Other comprehensive income (loss)	(145)							(142)		(142)	(3)
Total comprehensive income	5,602									4,418	1,184
Balance at Dec. 31, 2011	$ 18,553		$ 0	$ 0	$ 107	$ 19,007	$ 546	$ (465)	$ (3,553)	$ 15,642	$ 2,911
Balance (in shares) at Dec. 31, 2011			0	0	1,071				123

[1] Includes additional taxes of $57 million ($50 million net of noncontrolling interests or $0.05 per share) in the third quarter and $53 million ($49 million net of noncontrolling interests or $0.05 per share) for the year associated with Peru's new mining tax and royalty regime. Refer to Note 12 for for further discussion.