Inventories, Including Long-Term Mill and Leach Stockpiles (Unaudited) (Details) (USD $) In Millions	Jun. 30, 2011		Dec. 31, 2010
Components of Inventories [Line Items]
Total product inventories	$ 1,399		$ 1,409
Total materials and supplies, net	1,277	[1]	1,169	[1]
Total inventories, less current portion of mill and leach stockpiles	2,676		2,578
Inventory obsolescence reserves	23		26
Mining Operations [Member]
Components of Inventories [Line Items]
Raw materials	1		1
Work-in-process	78		93
Finished goods	745	[2]	704	[2]
Atlantic Copper [Member]
Components of Inventories [Line Items]
Raw materials	263		336
Work-in-process	297		266
Finished goods	$ 15		$ 9

[1] Materials and supplies inventory is net of obsolescence reserves totaling $23 million at June 30, 2011, and $26 million at December 31, 2010.

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