STOCKHOLDERS' EQUITY AND STOCK-BASED COMPENSATION (Details) (USD $)	1 Months Ended						12 Months Ended							13 Months Ended
	Apr. 30, 2011	Dec. 31, 2010	Oct. 31, 2010	Apr. 30, 2010	Oct. 31, 2009	Feb. 28, 2009	Dec. 31, 2011 years		Dec. 31, 2010		Dec. 31, 2009		Dec. 31, 2008	Jul. 31, 2008
Stockholders' Equity Note [Abstract]
FCX's authorized shares of capital stock													1,850,000,000
FCX's authorized shares of common stock													1,800,000,000
FCX's authorized shares of preferred stock													50,000,000
Number of shares outstanding as a result of stock split							945,000,000
Number of shares outstanding prior to stock split							472,000,000
Par value of common stock (in dollars per share)		$ 0.10					$ 0.10		$ 0.10
Number of shares authorized under open-market share purchase program														30,000,000
Shares acquired during 2008													6,300,000
Cost to acquire shares during 2008													$ 500,000,000
Average cost per share acquired during 2008													$ 79.15
Remaining shares available under the program													23,700,000
Public offering of FCX common stock						53,600,000
Average price used in the public offering of common stock						$ 14.00
Gross proceeds of the public offering of common stock						750,000,000
Net proceeds of the public offering of common stock						740,000,000	0		0		740,000,000
Authorized Annual Rate Of Common Stock Dividend			$ 1.00	$ 0.60	$ 0.30
Supplemental common stock dividend	$ 0.50	$ 0.50
Authorized Quarterly Rate Of Common Stock Dividend							$ 0.25
Stock-Based Compensation Cost [Abstract]
Stock options awarded to employees (including directors)							84,000,000		84,000,000		67,000,000
Stock options awarded to nonemployees							1,000,000		5,000,000		5,000,000
Restricted stock units awarded to employees (including directors)							32,000,000		30,000,000		29,000,000
Restricted stock awards to employees							0		1,000,000		2,000,000
Stock appreciation rights							(2,000,000)		2,000,000		4,000,000
Total stock-based compensation cost							115,000,000	[1]	122,000,000	[1]	107,000,000	[1]
Tax benefit							(42,000,000)		(45,000,000)		(41,000,000)
Noncontrolling interests' share							(4,000,000)		(3,000,000)		(3,000,000)
Impact on net income (loss)							69,000,000		74,000,000		63,000,000
Amount of joint venture partner share of the cost of employee stock option exercises							3,000,000		4,000,000		2,000,000
Stock appreciation rights outstanding and included in stock options							69,672
Stock options and stock appreciation rights [Roll Forward]
Balance at beginning of period (in number of options)							26,930,444		24,921,594		19,705,894
Granted (in number of options)							4,230,500		8,303,000		7,302,000
Exercised (in number of options)							(3,044,174)		(6,081,650)		(1,571,874)
Expired/Forfeited (in number of options)							(149,625)		(212,500)		(514,426)
Balance at end of period (in number of options)		26,930,444					27,967,145		26,930,444		24,921,594		19,705,894
Stock options and stock appreciation rights, additional disclosures [Abstract]
Weighted-average exercise price at beginning of period (in dollars per option)							$ 30.22		$ 27.59		$ 32.49
Granted (in dollars per option)		$ 36.15					$ 55.43		$ 36.15		$ 12.94
Exercised (in dollars per option)		$ 27.54					$ 21.88		$ 27.54		$ 20.15
Expired/Forfeited (in dollars per option)							$ 37.61		$ 30.29		$ 30.29
Weighted-average exercise price at end of period (in dollars per option)		$ 30.22					$ 34.90		$ 30.22		$ 27.59		$ 32.49
Weighted-average remaining contractual term (in years)							6.9
Aggregate intrinsic value of outstanding							152,000,000
Vested and exercisable at end of period (in options)							13,560,645
Weighted-average option price of vested and exercisable (in dollars per option)							$ 33.10
Weighted-average remaining contractual term of vested and exercisable (in years)							5.7
Aggregate intrinsic value of vested and exercisable							65,000,000
Fair value assumptions and methodology [Abstract]
Weighted-average expected volatility (in hundredths)							50.90%		51.90%		70.60%
Expected life of options (in years)							4.3400		4.6100		4.3700
Weighted-average expected dividend rate (in hundredths)							1.80%		0.80%		0.00%
Risk free interest rate (in hundredths)							1.60%		2.20%		1.50%
Weighted-average grant-date fair value (in dollars per option)							$ 20.58		$ 15.33		$ 7.14
Total intrinsic value of options exercised							101,000,000		129,000,000		24,000,000
Fair value of options vested							89,000,000		61,000,000		70,000,000
Total unrecognized compensation cost related to unvested stock options expected to be recognized over a weighted-average period							101,000,000
Weighted-average period used in calculating unrecognized compensation cost, stock options							1.5
Summary of amounts related to exercises of stock options and SARs and vesting of restricted stock units and restricted stock awards [Abstract]
Shares tendered to pay exercise price and minimum required taxes (in shares)							936,811	[2]	934,099	[2]	542,786	[2]
Cash received from exercise of stock options							48,000,000		109,000,000		18,000,000
Actual tax benefit realized for tax deductions							45,000,000		50,000,000		21,000,000
Amount paid for employee taxes							45,000,000		28,000,000		12,000,000
Amount paid for exercised stock appreciation rights							1,000,000		1,000,000		1,000,000
Restricted Stock Units [Roll Forward]
Balance, beginning of period (in RSUs)							2,140,914
Granted (in RSUs)							381,636
Vested (in RSUs)							(1,257,274)
Forfeited (in RSUs)							0
Balance, end of period (in RSUs)		2,140,914					1,265,276		2,140,914
Weighted-average remaining contractual term for restricted stock units (in years)							1.4
Restricted Stock Units Outstanding Intrinsic Value							47,000,000
Total grant-date fair value of restricted stock units granted							21,000,000
Total intrinsic value of restricted stock units vested							69,000,000		50,000,000		22,000,000
Total unrecognized compensation cost related to unvested restricted stock units expected to be recognized over a weighted-average period							$ 2,000,000
Weighted-average period used in calculating unrecognized compensation costs, restricted stock units							less than one year

[1] Amounts are before Rio Tinto’s share of the cost of employee exercises of in-the-money stock options, which decreased consolidated selling, general and administrative expenses by $3 million in 2011, $4 million in 2010 and $2 million in 2009.

[2] Under terms of the related plans, upon exercise of stock options and vesting of restricted stock units and restricted stock awards, employees may tender FCX shares to FCX to pay the exercise price and/or the minimum required taxes.