Consolidated Statement of Equity (Unaudited) (USD $) In Millions, unless otherwise specified	Total	Total FCX Stockholders' Equity [Member]	Common Stock [Member]	Capital in Excess of Par Value [Member]	Retained Earnings (Deficit) [Member]	Accumulated Other Comprehensive Loss [Member]	Common Stock Held in Treasury [Member]	Noncontrolling Interest [Member]
Balance at Dec. 31, 2011	$ 18,553	$ 15,642	$ 107	$ 19,007	$ 546	$ (465)	$ (3,553)	$ 2,911
Balance (in shares) at Dec. 31, 2011			1,071				123
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercised and issued stock-based awards	14	14	0	14	0	0	0	0
Exercised and issued stock-based awards (in shares)			2				0
Stock-based compensation	77	77	0	77	0	0	0	0
Tax benefit for stock-based awards	6	6	0	6	0	0	0	0
Tender of shares for stock-based awards	(16)	(16)	0	7	0	0	(23)	0
Tender of shares for stock-based awards (in shares)			0				1
Dividends on common stock	(891)	(891)	0	0	(891)	0	0	0
Dividends to noncontrolling interests	(76)	0	0	0	0	0	0	(76)
Change in ownership interests	0	(17)	0	(17)	0	0	0	17
Contributions from noncontrolling interests	15							15
Total comprehensive income	3,061	2,324	0	0	2,298	26	0	737
Balance at Sep. 30, 2012	$ 20,743	$ 17,139	$ 107	$ 19,094	$ 1,953	$ (439)	$ (3,576)	$ 3,604
Balance (in shares) at Sep. 30, 2012			1,073				124