OWNERSHIP IN SUBSIDIARIES, JOINT VENTURES AND INVESTMENT IN PT SMELTING	12 Months Ended
Dec. 31, 2012
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 minerals district in the DRC, and copper and molybdenum conversion facilities. At December 31, 2012, FMC’s operating copper mines in North America were Morenci, Bagdad, Safford, Sierrita 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. In addition to copper, certain of FMC's North America copper mines also produce molybdenum concentrates. FMC also owns 100 percent of the Henderson and Climax molybdenum mines located in Colorado. At December 31, 2012, 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, certain of FMC's South America copper mines also produce molybdenum concentrates, gold and silver. At December 31, 2012, FMC owned an effective 56 percent interest in the Tenke minerals district in the DRC (refer to Note 14 for discussion of the change in ownership interest in 2012). In addition to copper, the Tenke minerals district also produces cobalt hydroxide. At December 31, 2012, FMC’s net assets totaled $18.2 billion and its accumulated deficit totaled $10.5 billion. FCX had $27 million in intercompany loans outstanding to FMC at December 31, 2012. FCX’s direct ownership in PT Freeport Indonesia totals 81.28 percent (refer to "Joint Ventures – Rio Tinto"). 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, 2012, PT Freeport Indonesia’s net assets totaled $4.1 billion and its retained earnings totaled $3.9 billion. As of December 31, 2012, FCX had no loans outstanding to PT Freeport Indonesia. FCX owns 100 percent of the outstanding Atlantic Copper common stock. At December 31, 2012, Atlantic Copper’s net liabilities totaled $57 million and its accumulated deficit totaled $451 million. FCX had $434 million in intercompany loans outstanding to Atlantic Copper at December 31, 2012. 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, 2012, FCX did not have any loans outstanding to Puncakjaya Power, PT Freeport Indonesia had infrastructure asset financing obligations payable to Puncakjaya Power totaling $71 million, and Puncakjaya Power had a receivable from PT Freeport Indonesia for $91 million, including Rio Tinto’s share. FCX consolidates PT Freeport Indonesia and Puncakjaya Power. FCX’s consolidated balance sheets reflect receivables of $20 million ($3 million in other accounts receivable and $17 million in long-term receivables) at December 31, 2012, and $23 million ($3 million in other accounts receivable and $20 million in long-term receivables) at December 31, 2011, 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 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 business interruption and property damage relating to the 2011 incidents affecting PT Freeport Indonesia's concentrate pipelines. As a result of these incidents, the 2011 specified amounts, before smelter recoveries, attributable 100 percent to PT Freeport Indonesia were reduced by 228 million pounds for copper and 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 $4 million at December 31, 2012, and $45 million at December 31, 2011. 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 69 million pounds of Morenci’s copper cathode from Sumitomo for $250 million during 2012. FCX had a receivable from Sumitomo of $49 million at December 31, 2012, and $12 million at December 31, 2011. Investment in PT Smelting. PT Smelting, an Indonesian company, operates a smelter and refinery in Gresik, Indonesia. PT Smelting's production capacity is 275,000 metric tons of copper per year. PT Freeport Indonesia owns 25 percent of the outstanding PT Smelting common stock, which is accounted for using the equity method (refer to Note 6 for further discussion). 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 $39 million at December 31, 2012, and $2 million at December 31, 2011) totaled $89 million at December 31, 2012, and $125 million at December 31, 2011. PT Smelting had project-specific debt, nonrecourse to PT Freeport Indonesia, totaling $240 million at December 31, 2012, and $320 million at December 31, 2011. PT Freeport Indonesia had a trade receivable from PT Smelting totaling $152 million at December 31, 2012, and $116 million at December 31, 2011.

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 minerals district in the DRC, and copper and molybdenum conversion facilities. At December 31, 2012, FMC’s operating copper mines in North America were Morenci, Bagdad, Safford, Sierrita 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. In addition to copper, certain of FMC's North America copper mines also produce molybdenum concentrates. FMC also owns 100 percent of the Henderson and Climax molybdenum mines located in Colorado. At December 31, 2012, 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, certain of FMC's South America copper mines also produce molybdenum concentrates, gold and silver. At December 31, 2012, FMC owned an effective 56 percent interest in the Tenke minerals district in the DRC (refer to Note 14 for discussion of the change in ownership interest in 2012). In addition to copper, the Tenke minerals district also produces cobalt hydroxide. At December 31, 2012, FMC’s net assets totaled $18.2 billion and its accumulated deficit totaled $10.5 billion. FCX had $27 million in intercompany loans outstanding to FMC at December 31, 2012.

FCX’s direct ownership in PT Freeport Indonesia totals 81.28 percent (refer to "Joint Ventures – Rio Tinto"). 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, 2012, PT Freeport Indonesia’s net assets totaled $4.1 billion and its retained earnings totaled $3.9 billion. As of December 31, 2012, FCX had no loans outstanding to PT Freeport Indonesia.

FCX owns 100 percent of the outstanding Atlantic Copper common stock. At December 31, 2012, Atlantic Copper’s net liabilities totaled $57 million and its accumulated deficit totaled $451 million. FCX had $434 million in intercompany loans outstanding to Atlantic Copper at December 31, 2012.

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, 2012, FCX did not have any loans outstanding to Puncakjaya Power, PT Freeport Indonesia had infrastructure asset financing obligations payable to Puncakjaya Power totaling $71 million, and Puncakjaya Power had a receivable from PT Freeport Indonesia for $91 million, including Rio Tinto’s share. FCX consolidates PT Freeport Indonesia and Puncakjaya Power. FCX’s consolidated balance sheets reflect receivables of $20 million ($3 million in other accounts receivable and $17 million in long-term receivables) at December 31, 2012, and $23 million ($3 million in other accounts receivable and $20 million in long-term receivables) at December 31, 2011, 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 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 business interruption and property damage relating to the 2011 incidents affecting PT Freeport Indonesia's concentrate pipelines. As a result of these incidents, the 2011 specified amounts, before smelter recoveries, attributable 100 percent to PT Freeport Indonesia were reduced by 228 million pounds for copper and 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 $4 million at December 31, 2012, and $45 million at December 31, 2011.

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 69 million pounds of Morenci’s copper cathode from Sumitomo for $250 million during 2012. FCX had a receivable from Sumitomo of $49 million at December 31, 2012, and $12 million at December 31, 2011.

Investment in PT Smelting. PT Smelting, an Indonesian company, operates a smelter and refinery in Gresik, Indonesia. PT Smelting's production capacity is 275,000 metric tons of copper per year. PT Freeport Indonesia owns 25 percent of the outstanding PT Smelting common stock, which is accounted for using the equity method (refer to Note 6 for further discussion).

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 $39 million at December 31, 2012, and $2 million at December 31, 2011) totaled $89 million at December 31, 2012, and $125 million at December 31, 2011. PT Smelting had project-specific debt, nonrecourse to PT Freeport Indonesia, totaling $240 million at December 31, 2012, and $320 million at December 31, 2011. PT Freeport Indonesia had a trade receivable from PT Smelting totaling $152 million at December 31, 2012, and $116 million at December 31, 2011.