OWNERSHIP IN SUBSIDIARIES, JOINT VENTURES AND INVESTMENT IN PT SMELTING	12 Months Ended
Dec. 31, 2011
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract]
Ownership In Subsidiaries Joint Ventures And Investment In PT Smelting	OWNERSHIP IN SUBSIDIARIES, JOINT VENTURES AND INVESTMENT IN PT SMELTING Ownership in Subsidiaries. FMC is a fully integrated producer of copper and molybdenum, with mines in North America, South America and the Tenke Fungurume minerals district in the DRC, and copper and molybdenum conversion facilities. At December 31, 2011, FMC’s operating copper mines in North America were Morenci, Sierrita, Bagdad, Safford and Miami located in Arizona, and Tyrone and Chino located in New Mexico. FCX has an 85 percent interest in Morenci (refer to “Joint Ventures – Sumitomo”) and owns 100 percent of the other North America copper mines. FMC also owns 100 percent of the Henderson molybdenum mine and the Climax molybdenum mine (construction activities are substantially complete with plans to commence production in 2012), which are located in Colorado. At December 31, 2011, operating copper mines in South America were Cerro Verde (53.56 percent owned) located in Peru, and El Abra (51 percent owned), Candelaria (80 percent owned) and Ojos del Salado (80 percent owned) located in Chile. In addition to copper and molybdenum, certain FMC mines produce other minerals, such as gold, silver and rhenium. At December 31, 2011, FMC owned an effective 57.75 percent interest in the Tenke Fungurume minerals district in the DRC (refer to Note 14 for discussion of the future change in ownership interest). In addition to copper, the Tenke Fungurume minerals district also produces cobalt hydroxide. At December 31, 2011, FMC’s net assets totaled $14.9 billion and its accumulated deficit totaled $13.1 billion. FCX had $109 million in loans outstanding to FMC at December 31, 2011. FCX’s direct ownership in PT Freeport Indonesia totals 81.28 percent. PT Indocopper Investama, an Indonesian company, owns 9.36 percent of PT Freeport Indonesia and FCX owns 100 percent of PT Indocopper Investama. At December 31, 2011, PT Freeport Indonesia’s net assets totaled $3.2 billion and its retained earnings totaled $3.1 billion. As of December 31, 2011, FCX had no loans outstanding to PT Freeport Indonesia. FCX owns 100 percent of the outstanding Atlantic Copper common stock. At December 31, 2011, Atlantic Copper’s net liabilities totaled $43 million and its accumulated deficit totaled $437 million. FCX had $586 million in loans outstanding to Atlantic Copper at December 31, 2011. FCX owns an 85.71 percent interest in PT Puncakjaya Power (Puncakjaya Power), the owner of assets supplying power to PT Freeport Indonesia’s operations, including the 3x65 megawatt coal-fired power facilities. PT Freeport Indonesia purchases power from Puncakjaya Power under infrastructure asset financing arrangements. At December 31, 2011, FCX did not have any loans outstanding to Puncakjaya Power, PT Freeport Indonesia had infrastructure asset financing obligations payable to Puncakjaya Power totaling $81 million, and Puncakjaya Power had a receivable from PT Freeport Indonesia for $106 million, including Rio Tinto’s share. FCX consolidates PT Freeport Indonesia and Puncakjaya Power. FCX’s consolidated balance sheets reflect receivables of $23 million ($3 million in other accounts receivable and $20 million in long-term receivables) at December 31, 2011, and $25 million ($2 million in other accounts receivable and $23 million in long-term receivables) at December 31, 2010, for Rio Tinto’s share of Puncakjaya Power’s receivable from PT Freeport Indonesia as provided for in FCX’s joint venture agreement with Rio Tinto. Joint Ventures. FCX has the following unincorporated joint ventures with third parties. Rio Tinto. FCX and Rio Tinto have established certain unincorporated joint ventures. Under the joint venture arrangements, Rio Tinto has a 40 percent interest in PT Freeport Indonesia’s Contract of Work and the option to participate in 40 percent of any other future exploration projects in Papua, Indonesia. Pursuant to the joint venture agreement, Rio Tinto has a 40 percent interest in certain assets and future production exceeding specified annual amounts of copper, gold and silver through 2021 in Block A of PT Freeport Indonesia’s Contract of Work, and, after 2021, a 40 percent interest in all production from Block A. All of PT Freeport Indonesia’s proven and probable reserves and its mining operations are located in the Block A area. Operating, nonexpansion capital and administrative costs are shared proportionately between PT Freeport Indonesia and Rio Tinto based on the ratio of (i) the incremental revenues from production from PT Freeport Indonesia’s most recent expansion completed in 1998 to (ii) total revenues from production from Block A, including production from PT Freeport Indonesia’s previously existing reserves. PT Freeport Indonesia will continue to receive 100 percent of the cash flow from specified annual amounts of copper, gold and silver through 2021 calculated by reference to its proven and probable reserves as of December 31, 1994, and 60 percent of all remaining cash flow. The agreement provides for adjustments to the specified annual amounts of copper, gold and silver attributable 100 percent to PT Freeport Indonesia upon the occurrence of certain events that cause an interruption in production to occur, including events such as the labor disruptions and the temporary suspension of milling operations at PT Freeport Indonesia from damage to the concentrate and fuel pipelines that occurred in 2011. As a result of the labor and pipeline disruptions, the 2011 specified amounts, before smelter recoveries, attributable 100 percent to PT Freeport Indonesia were reduced by approximately 228 million pounds for copper and approximately 224 thousand ounces for gold, which will be offset by identical increases in future periods. The payable to Rio Tinto for its share of joint venture cash flows was $45 million at December 31, 2011, and $132 million at December 31, 2010. Under the joint venture arrangements, Rio Tinto funded $100 million in 1996 for approved exploration costs in the areas covered by Contracts of Work held by FCX subsidiaries. Agreed-upon exploration costs in the joint venture areas are shared 60 percent by FCX and 40 percent by Rio Tinto. Since September 2008, Rio Tinto is no longer participating in exploration joint ventures in the PT Nabire Bakti Mining and PT Irja Eastern Minerals Contract of Work areas in Indonesia. As a result, as long as Rio Tinto continues not to fund these exploration projects, FCX has the option to fund 100 percent of future exploration costs in these areas and Rio Tinto's interest in these areas will decline over time in accordance with the joint venture agreement. Rio Tinto has the option to resume participation in PT Irja Eastern Minerals on a monthly basis and in PT Nabire Bakti Mining on an annual basis. Rio Tinto continues to participate in exploration joint ventures in PT Freeport Indonesia's Contract of Work areas. Sumitomo. FCX owns an 85 percent undivided interest in Morenci via an unincorporated joint venture. The remaining 15 percent is owned by Sumitomo, a jointly owned subsidiary of Sumitomo Metal Mining Co., Ltd. and Sumitomo Corporation. Each partner takes in kind its share of Morenci’s production. FMC purchased 67 million pounds of Morenci’s copper cathode from Sumitomo for $268 million during 2011, 66 million pounds for $223 million during 2010 and 75 million pounds for $175 million during 2009. FCX had a receivable from Sumitomo of $12 million at December 31, 2011, and $8 million at December 31, 2010. Investment in PT Smelting. PT Smelting, an Indonesian company, operates a smelter and refinery in Gresik, Indonesia. During 2006, PT Smelting completed an expansion of its production capacity to 275,000 metric tons of copper per year from 250,000 metric tons. PT Freeport Indonesia owns 25 percent of the outstanding PT Smelting common stock. PT Freeport Indonesia’s contract with PT Smelting provides for the supply of 100 percent of the copper concentrate requirements necessary for PT Smelting to produce 205,000 metric tons of copper annually (essentially the smelter’s original design capacity) on a priority basis. For the first 15 years of PT Smelting’s commercial operations, beginning December 1998, PT Freeport Indonesia agreed that the combined treatment and refining charges would approximate market rates, but will not fall below specified minimum rates. The minimum rate, applicable to the period April 27, 2008, to April 27, 2014, is determined annually and must be sufficient to cover PT Smelting’s annual cash operating costs (net of credits and including costs of debt service) for 205,000 metric tons of copper. The maximum rate is $0.30 per pound. PT Freeport Indonesia also sells copper concentrate to PT Smelting at market rates, which are not subject to a minimum or maximum rate, for quantities in excess of 205,000 metric tons of copper annually. FCX’s investment in PT Smelting (net of PT Freeport Indonesia's share of profits on sales to PT Smelting still in PT Smelting's inventory totaling $2 million at December 31, 2011, and $113 million at December 31, 2010) totaled $125 million at December 31, 2011, and $11 million at December 31, 2010. PT Smelting had project-specific debt, nonrecourse to PT Freeport Indonesia, totaling $320 million at December 31, 2011, and $180 million at December 31, 2010. PT Freeport Indonesia had a trade receivable from PT Smelting totaling $116 million at December 31, 2011, and $455 million at December 31, 2010.

OWNERSHIP IN SUBSIDIARIES, JOINT VENTURES AND INVESTMENT IN PT SMELTING

Ownership in Subsidiaries. FMC is a fully integrated producer of copper and molybdenum, with mines in North America, South America and the Tenke Fungurume minerals district in the DRC, and copper and molybdenum conversion facilities. At December 31, 2011, FMC’s operating copper mines in North America were Morenci, Sierrita, Bagdad, Safford and Miami located in Arizona, and Tyrone and Chino located in New Mexico. FCX has an 85 percent interest in Morenci (refer to “Joint Ventures – Sumitomo”) and owns 100 percent of the other North America copper mines. FMC also owns 100 percent of the Henderson molybdenum mine and the Climax molybdenum mine (construction activities are substantially complete with plans to commence production in 2012), which are located in Colorado. At December 31, 2011, operating copper mines in South America were Cerro Verde (53.56 percent owned) located in Peru, and El Abra (51 percent owned), Candelaria (80 percent owned) and Ojos del Salado (80 percent owned) located in Chile. In addition to copper and molybdenum, certain FMC mines produce other minerals, such as gold, silver and rhenium. At December 31, 2011, FMC owned an effective 57.75 percent interest in the Tenke Fungurume minerals district in the DRC (refer to Note 14 for discussion of the future change in ownership interest). In addition to copper, the Tenke Fungurume minerals district also produces cobalt hydroxide. At December 31, 2011, FMC’s net assets totaled $14.9 billion and its accumulated deficit totaled $13.1 billion. FCX had $109 million in loans outstanding to FMC at December 31, 2011.

FCX’s direct ownership in PT Freeport Indonesia totals 81.28 percent. PT Indocopper Investama, an Indonesian company, owns 9.36 percent of PT Freeport Indonesia and FCX owns 100 percent of PT Indocopper Investama. At December 31, 2011, PT Freeport Indonesia’s net assets totaled $3.2 billion and its retained earnings totaled $3.1 billion. As of December 31, 2011, FCX had no loans outstanding to PT Freeport Indonesia.

FCX owns 100 percent of the outstanding Atlantic Copper common stock. At December 31, 2011, Atlantic Copper’s net liabilities totaled $43 million and its accumulated deficit totaled $437 million. FCX had $586 million in loans outstanding to Atlantic Copper at December 31, 2011.

FCX owns an 85.71 percent interest in PT Puncakjaya Power (Puncakjaya Power), the owner of assets supplying power to PT Freeport Indonesia’s operations, including the 3x65 megawatt coal-fired power facilities. PT Freeport Indonesia purchases power from Puncakjaya Power under infrastructure asset financing arrangements. At December 31, 2011, FCX did not have any loans outstanding to Puncakjaya Power, PT Freeport Indonesia had infrastructure asset financing obligations payable to Puncakjaya Power totaling $81 million, and Puncakjaya Power had a receivable from PT Freeport Indonesia for $106 million, including Rio Tinto’s share. FCX consolidates PT Freeport Indonesia and Puncakjaya Power. FCX’s consolidated balance sheets reflect receivables of $23 million ($3 million in other accounts receivable and $20 million in long-term receivables) at December 31, 2011, and $25 million ($2 million in other accounts receivable and $23 million in long-term receivables) at December 31, 2010, for Rio Tinto’s share of Puncakjaya Power’s receivable from PT Freeport Indonesia as provided for in FCX’s joint venture agreement with Rio Tinto.

Joint Ventures. FCX has the following unincorporated joint ventures with third parties.

Rio Tinto. FCX and Rio Tinto have established certain unincorporated joint ventures. Under the joint venture arrangements, Rio Tinto has a 40 percent interest in PT Freeport Indonesia’s Contract of Work and the option to participate in 40 percent of any other future exploration projects in Papua, Indonesia.

Pursuant to the joint venture agreement, Rio Tinto has a 40 percent interest in certain assets and future production exceeding specified annual amounts of copper, gold and silver through 2021 in Block A of PT Freeport Indonesia’s Contract of Work, and, after 2021, a 40 percent interest in all production from Block A. All of PT Freeport Indonesia’s proven and probable reserves and its mining operations are located in the Block A area. Operating, nonexpansion capital and administrative costs are shared proportionately between PT Freeport Indonesia and Rio Tinto based on the ratio of (i) the incremental revenues from production from PT Freeport Indonesia’s most recent expansion completed in 1998 to (ii) total revenues from production from Block A, including production from PT Freeport Indonesia’s previously existing reserves. PT Freeport Indonesia will continue to receive 100 percent of the cash flow from specified annual amounts of copper, gold and silver through 2021 calculated by reference to its proven and probable reserves as of December 31, 1994, and 60 percent of all remaining cash flow. The agreement provides for adjustments to the specified annual amounts of copper, gold and silver attributable 100 percent to PT Freeport Indonesia upon the occurrence of certain events that cause an interruption in production to occur, including events such as the labor disruptions and the temporary suspension of milling operations at PT Freeport Indonesia from damage to the concentrate and fuel pipelines that occurred in 2011. As a result of the labor and pipeline disruptions, the 2011 specified amounts, before smelter recoveries, attributable 100 percent to PT Freeport Indonesia were reduced by approximately 228 million pounds for copper and approximately 224 thousand ounces for gold, which will be offset by identical increases in future periods. The payable to Rio Tinto for its share of joint venture cash flows was $45 million at December 31, 2011, and $132 million at December 31, 2010.

Under the joint venture arrangements, Rio Tinto funded $100 million in 1996 for approved exploration costs in the areas covered by Contracts of Work held by FCX subsidiaries. Agreed-upon exploration costs in the joint venture areas are shared 60 percent by FCX and 40 percent by Rio Tinto. Since September 2008, Rio Tinto is no longer participating in exploration joint ventures in the PT Nabire Bakti Mining and PT Irja Eastern Minerals Contract of Work areas in Indonesia. As a result, as long as Rio Tinto continues not to fund these exploration projects, FCX has the option to fund 100 percent of future exploration costs in these areas and Rio Tinto's interest in these areas will decline over time in accordance with the joint venture agreement. Rio Tinto has the option to resume participation in PT Irja Eastern Minerals on a monthly basis and in PT Nabire Bakti Mining on an annual basis. Rio Tinto continues to participate in exploration joint ventures in PT Freeport Indonesia's Contract of Work areas.

Sumitomo. FCX owns an 85 percent undivided interest in Morenci via an unincorporated joint venture. The remaining 15 percent is owned by Sumitomo, a jointly owned subsidiary of Sumitomo Metal Mining Co., Ltd. and Sumitomo Corporation. Each partner takes in kind its share of Morenci’s production. FMC purchased 67 million pounds of Morenci’s copper cathode from Sumitomo for $268 million during 2011, 66 million pounds for $223 million during 2010 and 75 million pounds for $175 million during 2009. FCX had a receivable from Sumitomo of $12 million at December 31, 2011, and $8 million at December 31, 2010.

Investment in PT Smelting. PT Smelting, an Indonesian company, operates a smelter and refinery in Gresik, Indonesia. During 2006, PT Smelting completed an expansion of its production capacity to 275,000 metric tons of copper per year from 250,000 metric tons. PT Freeport Indonesia owns 25 percent of the outstanding PT Smelting common stock.

PT Freeport Indonesia’s contract with PT Smelting provides for the supply of 100 percent of the copper concentrate requirements necessary for PT Smelting to produce 205,000 metric tons of copper annually (essentially the smelter’s original design capacity) on a priority basis. For the first 15 years of PT Smelting’s commercial operations, beginning December 1998, PT Freeport Indonesia agreed that the combined treatment and refining charges would approximate market rates, but will not fall below specified minimum rates. The minimum rate, applicable to the period April 27, 2008, to April 27, 2014, is determined annually and must be sufficient to cover PT Smelting’s annual cash operating costs (net of credits and including costs of debt service) for 205,000 metric tons of copper. The maximum rate is $0.30 per pound. PT Freeport Indonesia also sells copper concentrate to PT Smelting at market rates, which are not subject to a minimum or maximum rate, for quantities in excess of 205,000 metric tons of copper annually.

FCX’s investment in PT Smelting (net of PT Freeport Indonesia's share of profits on sales to PT Smelting still in PT Smelting's inventory totaling $2 million at December 31, 2011, and $113 million at December 31, 2010) totaled $125 million at December 31, 2011, and $11 million at December 31, 2010. PT Smelting had project-specific debt, nonrecourse to PT Freeport Indonesia, totaling $320 million at December 31, 2011, and $180 million at December 31, 2010. PT Freeport Indonesia had a trade receivable from PT Smelting totaling $116 million at December 31, 2011, and $455 million at December 31, 2010.