Contingencies and Commitments (Unaudited) (Details) (USD $) In Millions, unless otherwise specified													3 Months Ended
	Mar. 31, 2012 PT Freeport Indonesia [Member]	Mar. 31, 2012 PT Freeport Indonesia [Member] Tax Assessment [Member]	Mar. 31, 2012 PT Freeport Indonesia [Member] Interest Assessment [Member]	Oct. 31, 2010 PT Freeport Indonesia [Member] Relating To 2005 [Member]	Oct. 31, 2010 PT Freeport Indonesia [Member] Relating To 2005 [Member] Tax Assessment [Member]	Oct. 31, 2010 PT Freeport Indonesia [Member] Relating To 2005 [Member] Interest Assessment [Member]	Nov. 30, 2011 PT Freeport Indonesia [Member] Relating To 2006 [Member]	Nov. 30, 2011 PT Freeport Indonesia [Member] Relating To 2006 [Member] Tax Assessment [Member]	Nov. 30, 2011 PT Freeport Indonesia [Member] Relating To 2006 [Member] Interest Assessment [Member]	Mar. 31, 2012 PT Freeport Indonesia [Member] Relating To 2007 [Member]	Mar. 31, 2012 PT Freeport Indonesia [Member] Relating To 2007 [Member] Tax Assessment [Member]	Mar. 31, 2012 PT Freeport Indonesia [Member] Relating To 2007 [Member] Interest Assessment [Member]	Mar. 31, 2012 Tenke Fungurume [Member]	Mar. 26, 2012 Tenke Fungurume [Member]	Dec. 31, 2011 Tenke Fungurume [Member]
Loss Contingencies [Line Items]
Foreign government assessment in connection with alleged obligations	$ 325	$ 219	$ 106	$ 158	$ 106	$ 52	$ 32	$ 22	$ 10	$ 135	$ 91	$ 44
Disputed Tax Assessments paid	158
Disputed tax assessments paid, long-term portion	124
Company's direct ownership percentage (in hundredths)														56.00%	57.75%
Amount Of Intercompany Loans Converted To Equity													$ 50