Inventories, Including Long-Term Mill and Leach Stockpiles (Unaudited) Mill and Leach Stockpiles (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Current:
Mill stockpiles	$ 85		$ 69
Leach stockpiles	1,307		1,220
Total current mill and leach stockpiles	1,392		1,289
Long Term:
Mill stockpiles	549	[1]	535	[1]
Leach stockpiles	1,198	[1]	1,151	[1]
Total long-term mill and leach stockpiles	$ 1,747	[1]	$ 1,686	[1]

[1] Metals in stockpiles not expected to be recovered within the next 12 months.