Other Events	12 Months Ended
Dec. 31, 2018
Resource Management, Acquisitions and Other Commercial Events [Abstract]
Resource Management, Acquisitions and Other Commercial Events	Other Events North Goonyella The Company’s North Goonyella Mine in Queensland, Australia experienced a fire in a portion of the mine during September 2018. The underground mine and portions of the surface area remain restricted to access through exclusion zones as mine management continues to evaluate the impact of the fire on the mine and determine potential next phases, including establishing protocols and implementing procedures for re-ventilating and re-entering portions of the mine. Mining operations have been suspended since September 2018. No mine personnel were physically harmed by the September 2018 events. On November 13, 2018 the Queensland Mine Inspectorate (QMI) initiated an investigation into the events that occurred at the mine to determine the cause of the event, assess the response to it and make recommendations to reduce the possibility of future incidents and improve response. The QMI has issued an initial series of document and records requests to the Company, and formal witness interviews are anticipated to follow. Since the investigation is in its early phases, the outcome is presently unknown and subject to numerous uncertainties. During the year ended December 31, 2018, the Company recorded $58.0 million in containment and idling costs related to the events at North Goonyella and a provision of $66.4 million for expected equipment losses. This provision includes $50.4 million for the estimated cost to replace leased equipment and $16.0 million related to the cost of Company-owned equipment. This provision represents the best estimate of potential loss based on the assessments made to date. In the event that no future mining occurs at the North Goonyella Mine, the Company may record additional charges for the remaining carrying value of the North Goonyella Mine and additional leased equipment of approximately $285 million and $16 million, respectively. Incremental exposures include take-or-pay obligations and other costs associated with idling or closing the mine. The Company filed an insurance claim against applicable insurance policies with combined property damage and business interruption loss limits of $125 million above a $50 million deductible. Divestitures and Other Transactions In June 2018, Peabody entered into an agreement to sell approximately 23 million tonnes of metallurgical coal resources adjacent to its Millennium Mine to Stanmore Coal Limited (Stanmore) for approximately $22 million. The sale was completed in July 2018 and the Company recorded a gain of $20.5 million which is included within “Net gain on disposals” in the accompanying consolidated statements of operations for the year ended December 31, 2018. As of December 31, 2018, Stanmore has paid Peabody approximately $7 million, and the remaining balance, which will be paid over the subsequent seven months, is included in “Accounts receivable, net” in the accompanying consolidated balance sheet. On February 6, 2018, the Company sold its 50% interest in the Red Mountain Joint Venture (RMJV) with BHP Billiton Mitsui Coal Pty Ltd (BMC) for $20.0 million and recorded a gain of $7.1 million, which is included within “Net gain on disposals” in the accompanying consolidated statements of operations for the year ended December 31, 2018. RMJV operated the coal handling and preparation plant utilized by the Company’s Millennium Mine. BMC assumed the reclamation obligations and other commitments associated with the assets of RMJV. The Millennium Mine will have continued usage of the coal handling and preparation plant and the associated rail loading facility until the end of 2019 via a coal washing take-or-pay agreement with BMC. In January 2018, Peabody entered into an agreement to sell its share in certain surplus land assets in Queensland’s Bowen Basin to Pembroke Resources South Pty Ltd for approximately $37 million Australian dollars, net of transaction costs. The necessary approval of the Australian Foreign Investment Review Board to complete the transaction was received on March 29, 2018, satisfying all the conditions precedent to the sale, and the Company recorded a gain of $20.6 million, which is included within “Net gain on disposals” in the accompanying consolidated statements of operations for the year ended December 31, 2018. On November 28, 2017, the Company paid $3.0 million for a third-party’s assumption of all rights and obligations related to a guarantee liability recorded pursuant to a 2007 transaction wherein the Company purchased approximately 345 million tons of coal reserves and surface lands in the Illinois Basin. In conjunction with the 2007 purchase, the Company agreed to guarantee certain reclamation and bonding commitments of an affiliate of the seller. The Company extinguished its associated $34.2 million liability upon completion of the 2017 transaction and recorded a gain of $31.2 million which is included within “Net gain on disposals” in the accompanying consolidated statements of operations for the period April 2 through December 31, 2017. On November 27, 2017, the Company completed the sale of the majority of its Burton Mine and related infrastructure to the Lenton Joint Venture for $11.7 million. The Lenton Joint Venture assumed the reclamation obligations associated with the assets acquired in the sale. The transaction reduced the Company’s asset retirement obligation by $40.5 million and reduced the amount of restricted cash held in support of such obligations by approximately $30 million. The Burton Mine, located in Queensland’s Bowen Basin, entered a care, maintenance and rehabilitation phase in December 2016 and had no carrying value at the time of sale. In connection with the transaction, the Company recorded a gain of $52.2 million which is included within “Net gain on disposals” in the accompanying consolidated statements of operations for the period April 2 through December 31, 2017. The Company had a 37.5% interest in Dominion Terminal Associates, a partnership that operates a coal export terminal in Newport News, Virginia that exports both metallurgical and thermal coal primarily to Europe and Brazil. On March 31, 2017, the Company completed a sale of its interest in Dominion Terminal Associates to Contura Terminal, LLC and Ashland Terminal, Inc., both of which are partners of the Dominion Terminal Associates. The Company collected $20.5 million in proceeds and recorded $19.7 million of gain on the sale, which was classified in “Net gain on disposals” in the consolidated statement of operations during the period January 1 through April 1, 2017. In November 2016, the Company entered into a definitive share sale and purchase agreement (SPA) for the sale of all of its equity interest in Metropolitan Collieries Pty Ltd, the entity that owns the Metropolitan Mine in New South Wales, Australia and the associated interest in the Port Kembla Coal Terminal, to South32 Limited (South32). The SPA provided for a cash purchase price of $200.0 million and certain contingent consideration, subject to a customary working capital adjustment. South32 terminated the agreement in April 2017 after it was unable to obtain necessary approvals from the Australian Competition and Consumer Commission within the timeframe required under the SPA. As a result of the termination, the Company retained an earnest deposit posted by South32 which was recorded in “Revenues” in the accompanying consolidated statements of operations during the period April 2 through December 31, 2017. In May 2016, the Company completed the sale of its 5.06% participation interest in the Prairie State Energy Campus to the Wabash Valley Power Association for $57.1 million. The Company recognized a gain on sale of $6.2 million related to the transaction, which was classified in “Net gain on disposals” in the consolidated statement of operations for the year ended December 31, 2016. In May 2016, the Company entered into sale and purchase agreements with Australia-based Pembroke Resources to sell its interest in undeveloped metallurgical reserve tenements in Queensland’s Bowen Basin. The transaction included Olive Downs South, Olive Downs South Extended and Willunga tenements, which were sold for $64.1 million in cash plus a royalty stream. The Company recognized a gain on sale of $2.8 million related to those tenements, which was classified in “Net gain on disposals” in the consolidated statement of operations for the year ended December 31, 2016. The sale and purchase agreement for the remaining tenements, namely the Olive Downs North tenements, terminated in October 2017 as certain closing conditions were not satisfied within the prescribed time period. In November 2015, the Company entered into a definitive agreement to sell its New Mexico and Colorado assets to Bowie Resource Partners, LLC (Bowie) in exchange for cash proceeds of $358 million and the assumption of certain liabilities. Bowie agreed to pay the Company a termination fee of $20 million (Termination Fee) in the event the Company terminated the agreement because Bowie failed to obtain financing and close the transaction. On April 12, 2016, Peabody terminated the agreement and demanded payment of the Termination Fee. Following a favorable judgment by the Bankruptcy Court, the Company collected the Termination Fee from Bowie. The Termination Fee is included in “Revenues” in the accompanying consolidated statements of operations during the period April 2 through December 31, 2017. Joint Venture In 2014, the Company agreed to establish an unincorporated joint venture project with Glencore plc (Glencore), in which the Company holds a 50% interest, to combine the existing operations of the Company’s Wambo Open-Cut Mine in Australia with the adjacent coal reserves of Glencore’s United Mine. The Company expects the project to result in several operational synergies, including improved mining productivity, lower per-unit operating costs and an extended mine life. The joint venture is expected to be formed during the first half of 2019, subject to substantive contingencies, including the requisite regulatory and permitting approvals. At such time as control over the existing open-cut operations is exchanged, the Company will account for its interest in the combined operations at fair value.

Other Events

North Goonyella

The Company’s North Goonyella Mine in Queensland, Australia experienced a fire in a portion of the mine during September 2018. The underground mine and portions of the surface area remain restricted to access through exclusion zones as mine management continues to evaluate the impact of the fire on the mine and determine potential next phases, including establishing protocols and implementing procedures for re-ventilating and re-entering portions of the mine. Mining operations have been suspended since September 2018. No mine personnel were physically harmed by the September 2018 events. On November 13, 2018 the Queensland Mine Inspectorate (QMI) initiated an investigation into the events that occurred at the mine to determine the cause of the event, assess the response to it and make recommendations to reduce the possibility of future incidents and improve response. The QMI has issued an initial series of document and records requests to the Company, and formal witness interviews are anticipated to follow. Since the investigation is in its early phases, the outcome is presently unknown and subject to numerous uncertainties.

During the year ended December 31, 2018, the Company recorded $58.0 million in containment and idling costs related to the events at North Goonyella and a provision of $66.4 million for expected equipment losses. This provision includes $50.4 million for the estimated cost to replace leased equipment and $16.0 million related to the cost of Company-owned equipment. This provision represents the best estimate of potential loss based on the assessments made to date. In the event that no future mining occurs at the North Goonyella Mine, the Company may record additional charges for the remaining carrying value of the North Goonyella Mine and additional leased equipment of approximately $285 million and $16 million, respectively. Incremental exposures include take-or-pay obligations and other costs associated with idling or closing the mine. The Company filed an insurance claim against applicable insurance policies with combined property damage and business interruption loss limits of $125 million above a $50 million deductible.

Divestitures and Other Transactions

In June 2018, Peabody entered into an agreement to sell approximately 23 million tonnes of metallurgical coal resources adjacent to its Millennium Mine to Stanmore Coal Limited (Stanmore) for approximately $22 million. The sale was completed in July 2018 and the Company recorded a gain of $20.5 million which is included within “Net gain on disposals” in the accompanying consolidated statements of operations for the year ended December 31, 2018. As of December 31, 2018, Stanmore has paid Peabody approximately $7 million, and the remaining balance, which will be paid over the subsequent seven months, is included in “Accounts receivable, net” in the accompanying consolidated balance sheet.

On February 6, 2018, the Company sold its 50% interest in the Red Mountain Joint Venture (RMJV) with BHP Billiton Mitsui Coal Pty Ltd (BMC) for $20.0 million and recorded a gain of $7.1 million, which is included within “Net gain on disposals” in the accompanying consolidated statements of operations for the year ended December 31, 2018. RMJV operated the coal handling and preparation plant utilized by the Company’s Millennium Mine. BMC assumed the reclamation obligations and other commitments associated with the assets of RMJV. The Millennium Mine will have continued usage of the coal handling and preparation plant and the associated rail loading facility until the end of 2019 via a coal washing take-or-pay agreement with BMC.

In January 2018, Peabody entered into an agreement to sell its share in certain surplus land assets in Queensland’s Bowen Basin to Pembroke Resources South Pty Ltd for approximately $37 million Australian dollars, net of transaction costs. The necessary approval of the Australian Foreign Investment Review Board to complete the transaction was received on March 29, 2018, satisfying all the conditions precedent to the sale, and the Company recorded a gain of $20.6 million, which is included within “Net gain on disposals” in the accompanying consolidated statements of operations for the year ended December 31, 2018.

On November 28, 2017, the Company paid $3.0 million for a third-party’s assumption of all rights and obligations related to a guarantee liability recorded pursuant to a 2007 transaction wherein the Company purchased approximately 345 million tons of coal reserves and surface lands in the Illinois Basin. In conjunction with the 2007 purchase, the Company agreed to guarantee certain reclamation and bonding commitments of an affiliate of the seller. The Company extinguished its associated $34.2 million liability upon completion of the 2017 transaction and recorded a gain of $31.2 million which is included within “Net gain on disposals” in the accompanying consolidated statements of operations for the period April 2 through December 31, 2017.

On November 27, 2017, the Company completed the sale of the majority of its Burton Mine and related infrastructure to the Lenton Joint Venture for $11.7 million. The Lenton Joint Venture assumed the reclamation obligations associated with the assets acquired in the sale. The transaction reduced the Company’s asset retirement obligation by $40.5 million and reduced the amount of restricted cash held in support of such obligations by approximately $30 million. The Burton Mine, located in Queensland’s Bowen Basin, entered a care, maintenance and rehabilitation phase in December 2016 and had no carrying value at the time of sale. In connection with the transaction, the Company recorded a gain of $52.2 million which is included within “Net gain on disposals” in the accompanying consolidated statements of operations for the period April 2 through December 31, 2017.

The Company had a 37.5% interest in Dominion Terminal Associates, a partnership that operates a coal export terminal in Newport News, Virginia that exports both metallurgical and thermal coal primarily to Europe and Brazil. On March 31, 2017, the Company completed a sale of its interest in Dominion Terminal Associates to Contura Terminal, LLC and Ashland Terminal, Inc., both of which are partners of the Dominion Terminal Associates. The Company collected $20.5 million in proceeds and recorded $19.7 million of gain on the sale, which was classified in “Net gain on disposals” in the consolidated statement of operations during the period January 1 through April 1, 2017.

In November 2016, the Company entered into a definitive share sale and purchase agreement (SPA) for the sale of all of its equity interest in Metropolitan Collieries Pty Ltd, the entity that owns the Metropolitan Mine in New South Wales, Australia and the associated interest in the Port Kembla Coal Terminal, to South32 Limited (South32). The SPA provided for a cash purchase price of $200.0 million and certain contingent consideration, subject to a customary working capital adjustment. South32 terminated the agreement in April 2017 after it was unable to obtain necessary approvals from the Australian Competition and Consumer Commission within the timeframe required under the SPA. As a result of the termination, the Company retained an earnest deposit posted by South32 which was recorded in “Revenues” in the accompanying consolidated statements of operations during the period April 2 through December 31, 2017.

In May 2016, the Company completed the sale of its 5.06% participation interest in the Prairie State Energy Campus to the Wabash Valley Power Association for $57.1 million. The Company recognized a gain on sale of $6.2 million related to the transaction, which was classified in “Net gain on disposals” in the consolidated statement of operations for the year ended December 31, 2016.

In May 2016, the Company entered into sale and purchase agreements with Australia-based Pembroke Resources to sell its interest in undeveloped metallurgical reserve tenements in Queensland’s Bowen Basin. The transaction included Olive Downs South, Olive Downs South Extended and Willunga tenements, which were sold for $64.1 million in cash plus a royalty stream. The Company recognized a gain on sale of $2.8 million related to those tenements, which was classified in “Net gain on disposals” in the consolidated statement of operations for the year ended December 31, 2016. The sale and purchase agreement for the remaining tenements, namely the Olive Downs North tenements, terminated in October 2017 as certain closing conditions were not satisfied within the prescribed time period.

In November 2015, the Company entered into a definitive agreement to sell its New Mexico and Colorado assets to Bowie Resource Partners, LLC (Bowie) in exchange for cash proceeds of $358 million and the assumption of certain liabilities. Bowie agreed to pay the Company a termination fee of $20 million (Termination Fee) in the event the Company terminated the agreement because Bowie failed to obtain financing and close the transaction. On April 12, 2016, Peabody terminated the agreement and demanded payment of the Termination Fee. Following a favorable judgment by the Bankruptcy Court, the Company collected the Termination Fee from Bowie. The Termination Fee is included in “Revenues” in the accompanying consolidated statements of operations during the period April 2 through December 31, 2017.

Joint Venture

In 2014, the Company agreed to establish an unincorporated joint venture project with Glencore plc (Glencore), in which the Company holds a 50% interest, to combine the existing operations of the Company’s Wambo Open-Cut Mine in Australia with the adjacent coal reserves of Glencore’s United Mine. The Company expects the project to result in several operational synergies, including improved mining productivity, lower per-unit operating costs and an extended mine life. The joint venture is expected to be formed during the first half of 2019, subject to substantive contingencies, including the requisite regulatory and permitting approvals. At such time as control over the existing open-cut operations is exchanged, the Company will account for its interest in the combined operations at fair value.