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 [Member]	Accumulated Other Comprehensive Loss [Member]	Common Stock Held in Treasury [Member]	Noncontrolling Interests [Member]
Balance at Dec. 31, 2012	$ 21,311	$ 17,543	$ 107	$ 19,119	$ 2,399	$ (506)	$ (3,576)	$ 3,768
Balance (in shares) at Dec. 31, 2012			1,073				124
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued to acquire Plains Exploration & Production Co.	2,831	2,831	9	2,822	0	0	0	0
Common stock issued to acquire Plains Exploration & Production Co. (in shares)			91				0
Exchange of employee stock-based awards in connection with acquisitions	67	67	0	67	0	0	0	0
Exercised and issued stock-based awards	5	5	1	4	0	0	0	0
Exercised and issued stock-based awards (in shares)			1				0
Stock-based compensation	89	89	0	89	0	0	0	0
Reserve on tax benefit for stock-based awards	(2)	(2)		(2)	0	0	0	0
Tender of shares for stock-based awards	(105)	(105)	0	0	0	0	(105)	0
Tender of shares for stock-based awards (in shares)			0				3
Dividends on common stock	(1,989)	(1,989)	0	0	(1,989)	0	0	0
Dividends to noncontrolling interests	(144)	0	0	0	0	0	0	(144)
Noncontrolling interests' share of contributed capital in subsidiary	0	(7)	0	(7)	0	0	0	7
Redeemable noncontrolling interest	(12)	0	0	0	0	0	0	(12)
Total comprehensive income	2,503	1,973	0	0	1,951	22	0	530
Balance at Sep. 30, 2013	$ 24,554	$ 20,405	$ 117	$ 22,092	$ 2,361	$ (484)	$ (3,681)	$ 4,149
Balance (in shares) at Sep. 30, 2013			1,165				127