Inventories, Including Long-Term Mill and Leach Stockpiles (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Components of Inventories [Line Items]
Total product inventories	$ 1,254		$ 1,226
Total materials and supplies, net	1,450	[1]	1,354	[1]
Total inventories, less current portion of mill and leach stockpiles	2,704		2,580
Inventory obsolescence reserves	27		26
Mining Operations [Member]
Components of Inventories [Line Items]
Raw materials	1	[2]	1	[2]
Finished goods	805	[2],[3]	769	[2],[3]
Atlantic Copper [Member]
Components of Inventories [Line Items]
Raw materials	218		260
Work-in-process	212		187
Finished goods	$ 18		$ 9

[1] Materials and supplies inventory is net of obsolescence reserves totaling $27 million at March 31, 2012, and $26 million at December 31, 2011.

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

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