Inventories, Including Long-Term Mill and Leach Stockpiles (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Components of Inventories [Line Items]
Total product inventories	$ 1,374		$ 1,226
Total materials and supplies, net	1,465	[1]	1,354	[1]
Total inventories, excluding mill and leach stockpiles	2,839		2,580
Inventory obsolescence reserves	26		26
Mining Operations [Member]
Components of Inventories [Line Items]
Raw materials	2	[2]	1	[2]
Finished goods	820	[2],[3]	769	[2],[3]
Atlantic Copper, S.L.U. (Atlantic Copper) [Member]
Components of Inventories [Line Items]
Raw materials	339		260
Work-in-process	191		187
Finished goods	$ 22		$ 9

[1] Materials and supplies inventory was net of obsolescence reserves totaling $26 million at September 30, 2012, and December 31, 2011.

[2] FCX's mining operations also have work-in-process inventories (i.e., mill and leach stockpiles), which are summarized below.

[3] Primarily included molybdenum concentrates and copper concentrates, anodes, cathodes and rod.