OWNERSHIP IN SUBSIDIARIES AND JOINT VENTURES	12 Months Ended
Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Ownership In Subsidiaries And Joint Ventures	OWNERSHIP IN SUBSIDIARIES AND JOINT VENTURES Ownership in Subsidiaries. FMC produces copper and molybdenum, with mines in North America and South America. At December 31, 2017, FMC’s operating mines in North America were Morenci, Bagdad, Safford, Sierrita and Miami located in Arizona; Tyrone and Chino located in New Mexico; and Henderson and Climax located in Colorado. FCX has a 72 percent interest (subsequent to the sale of a 13 percent undivided interest on May 31, 2016) in Morenci (refer to “Joint Ventures – Sumitomo and SMM Morenci, Inc.”) and owns 100 percent of the other North America mines. At December 31, 2017, operating mines in South America were Cerro Verde (53.56 percent owned) located in Peru and El Abra (51 percent owned) located in Chile. At December 31, 2017, FMC’s net assets totaled $16.0 billion and its accumulated deficit totaled $14.0 billion. FCX had no loans outstanding to FMC at December 31, 2017. FCX’s direct ownership in PT-FI totals 81.28 percent. PT Indocopper Investama, an Indonesian company, owns 9.36 percent of PT-FI, and FCX owns 100 percent of PT Indocopper Investama. Refer to “Joint Ventures - Rio Tinto” for discussion of the unincorporated joint venture. At December 31, 2017, PT-FI’s net assets totaled $6.3 billion and its retained earnings totaled $6.0 billion. FCX had no loans outstanding to PT-FI at December 31, 2017. FCX owns 100 percent of the outstanding Atlantic Copper common stock. At December 31, 2017, Atlantic Copper’s net liabilities totaled $40 million and its accumulated deficit totaled $452 million. FCX had $365 million in intercompany loans outstanding to Atlantic Copper at December 31, 2017. FCX owns 100 percent of FM O&G, which, as of December 31, 2017, has oil and gas assets that primarily includes oil and natural gas production onshore in South Louisiana and on the GOM Shelf and oil production offshore California. At December 31, 2017, FM O&G’s net liabilities totaled $13.7 billion and its accumulated deficit totaled $25.3 billion. FCX had $9.9 billion in intercompany loans outstanding to FM O&G at December 31, 2017. Joint Ventures. FCX has the following unincorporated joint ventures. Rio Tinto. PT-FI and Rio Tinto have established an unincorporated joint venture pursuant to which Rio Tinto has a 40 percent interest in PT-FI’s Contract of Work (COW) 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 2022 in Block A of PT-FI’s COW, and, after 2022, a 40 percent interest in all production from Block A. All of PT-FI’s proven and probable reserves and all its mining operations are located in the Block A area. PT-FI receives 100 percent of production and related revenues from reserves established as of December 31, 1994 (27.1 billion pounds of copper, 38.4 million ounces of gold and 75.8 million ounces of silver), divided into annual portions subject to reallocation for events causing changes in the anticipated production schedule. Production and related revenues exceeding those annual amounts (referred to as incremental expansion revenues) are shared 60 percent PT-FI and 40 percent Rio Tinto. Operating, nonexpansion capital and administrative costs are shared 60 percent PT-FI and 40 percent Rio Tinto based on the ratio of (i) the incremental expansion revenues to (ii) total revenues from production from Block A, with PT-FI responsible for the rest of such costs. PT-FI will continue to receive 100 percent of the cash flow from specified annual amounts of copper, gold and silver through 2022 calculated by reference to its proven and probable reserves as of December 31, 1994, and 60 percent of all remaining cash flow. Expansion capital costs are shared 60 percent PT-FI and 40 percent Rio Tinto. The payable to Rio Tinto for its share of joint venture cash flows was $30 million at December 31, 2017, and $10 million at December 31, 2016. Sumitomo and SMM Morenci, Inc. FMC owns a 72 percent undivided interest in Morenci via an unincorporated joint venture. The remaining 28 percent is owned by Sumitomo (15 percent) and SMM Morenci, Inc. (13 percent). Each partner takes in kind its share of Morenci’s production. FMC purchased 218 million pounds of Morenci’s copper cathode from Sumitomo and SMM Morenci, Inc. at market prices for $610 million during 2017. FMC had receivables from Sumitomo and SMM Morenci, Inc. totaling $18 million at December 31, 2017, and $15 million at December 31, 2016.

OWNERSHIP IN SUBSIDIARIES AND JOINT VENTURES

Ownership in Subsidiaries. FMC produces copper and molybdenum, with mines in North America and South America. At December 31, 2017, FMC’s operating mines in North America were Morenci, Bagdad, Safford, Sierrita and Miami located in Arizona; Tyrone and Chino located in New Mexico; and Henderson and Climax located in Colorado. FCX has a 72 percent interest (subsequent to the sale of a 13 percent undivided interest on May 31, 2016) in Morenci (refer to “Joint Ventures – Sumitomo and SMM Morenci, Inc.”) and owns 100 percent of the other North America mines. At December 31, 2017, operating mines in South America were Cerro Verde (53.56 percent owned) located in Peru and El Abra (51 percent owned) located in Chile. At December 31, 2017, FMC’s net assets totaled $16.0 billion and its accumulated deficit totaled $14.0 billion. FCX had no loans outstanding to FMC at December 31, 2017.

FCX’s direct ownership in PT-FI totals 81.28 percent. PT Indocopper Investama, an Indonesian company, owns 9.36 percent of PT-FI, and FCX owns 100 percent of PT Indocopper Investama. Refer to “Joint Ventures - Rio Tinto” for discussion of the unincorporated joint venture. At December 31, 2017, PT-FI’s net assets totaled $6.3 billion and its retained earnings totaled $6.0 billion. FCX had no loans outstanding to PT-FI at December 31, 2017.

FCX owns 100 percent of the outstanding Atlantic Copper common stock. At December 31, 2017, Atlantic Copper’s net liabilities totaled $40 million and its accumulated deficit totaled $452 million. FCX had $365 million in intercompany loans outstanding to Atlantic Copper at December 31, 2017.

FCX owns 100 percent of FM O&G, which, as of December 31, 2017, has oil and gas assets that primarily includes oil and natural gas production onshore in South Louisiana and on the GOM Shelf and oil production offshore California. At December 31, 2017, FM O&G’s net liabilities totaled $13.7 billion and its accumulated deficit totaled $25.3 billion. FCX had $9.9 billion in intercompany loans outstanding to FM O&G at December 31, 2017.

Joint Ventures. FCX has the following unincorporated joint ventures.

Rio Tinto. PT-FI and Rio Tinto have established an unincorporated joint venture pursuant to which Rio Tinto has a 40 percent interest in PT-FI’s Contract of Work (COW) 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 2022 in Block A of PT-FI’s COW, and, after 2022, a 40 percent interest in all production from Block A. All of PT-FI’s proven and probable reserves and all its mining operations are located in the Block A area. PT-FI receives 100 percent of production and related revenues from reserves established as of December 31, 1994 (27.1 billion pounds of copper, 38.4 million ounces of gold and 75.8 million ounces of silver), divided into annual portions subject to reallocation for events causing changes in the anticipated production schedule. Production and related revenues exceeding those annual amounts (referred to as incremental expansion revenues) are shared 60 percent PT-FI and 40 percent Rio Tinto. Operating, nonexpansion capital and administrative costs are shared 60 percent PT-FI and 40 percent Rio Tinto based on the ratio of (i) the incremental expansion revenues to (ii) total revenues from production from Block A, with PT-FI responsible for the rest of such costs. PT-FI will continue to receive 100 percent of the cash flow from specified annual amounts of copper, gold and silver through 2022 calculated by reference to its proven and probable reserves as of December 31, 1994, and 60 percent of all remaining cash flow. Expansion capital costs are shared 60 percent PT-FI and 40 percent Rio Tinto. The payable to Rio Tinto for its share of joint venture cash flows was $30 million at December 31, 2017, and $10 million at December 31, 2016.

Sumitomo and SMM Morenci, Inc. FMC owns a 72 percent undivided interest in Morenci via an unincorporated joint venture. The remaining 28 percent is owned by Sumitomo (15 percent) and SMM Morenci, Inc. (13 percent). Each partner takes in kind its share of Morenci’s production. FMC purchased 218 million pounds of Morenci’s copper cathode from Sumitomo and SMM Morenci, Inc. at market prices for $610 million during 2017. FMC had receivables from Sumitomo and SMM Morenci, Inc. totaling $18 million at December 31, 2017, and $15 million at December 31, 2016.