Other Events	12 Months Ended
Dec. 31, 2019
Resource Management, Acquisitions and Other Commercial Events [Abstract]
Resource Management, Acquisitions and Other Commercial Events	Other Events United Wambo Joint Venture with Glencore In December 2019, after receiving the requisite regulatory and permitting approvals, the Company formed an unincorporated joint venture 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 will proportionally consolidate the entity based upon its economic interest. Glencore will manage the mining operations of the joint venture (United Wambo Joint Venture). Both parties contributed mining tenements and other assets upon formation. The Company accounted for its interest in the United Wambo Joint Venture at fair value and recognized a gain of $48.1 million, which was classified in “Gain on formation of United Wambo Joint Venture” in the accompanying consolidated statements of operations during the year ended December 31, 2019. The gain represents the difference between the fair value of the Company’s interest in the joint venture, $63.7 million, and the carrying value of the Company’s net assets contributed upon formation, $15.6 million. The fair value of the Company’s interest in the joint venture is based on applying the income and cost valuation methods to the combined mining tenements and includes a provision for the estimated fair value of related asset retirement obligations. PRB Colorado Joint Venture with Arch On June 18, 2019, the Company entered into a definitive implementation agreement (the Implementation Agreement) with Arch, to establish a joint venture that will combine the respective Powder River Basin and Colorado operations of Peabody and Arch. Pursuant to the terms of the Implementation Agreement, Peabody will hold a 66.5% economic interest in the joint venture and Arch will hold a 33.5% economic interest. The Company expects to proportionally consolidate the entity based upon its economic interest. Governance of the joint venture will be overseen by the joint venture’s board of managers, which will be comprised of Peabody and Arch representatives with voting powers proportionate with the companies’ economic interests, with the exception of certain specified matters which will require supermajority approval. Peabody will manage the operations of the joint venture, subject to the supervision of the joint venture’s board of managers. Formation of the joint venture is subject to customary closing conditions, including the termination or expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, the receipt of certain other required regulatory approvals and the absence of injunctions or other legal restraints preventing the formation of the joint venture. The proposed joint venture is progressing through the U.S. Federal Trade Commission regulatory review process and the Company expects a decision in the first quarter, which would result in the clearance to form the joint venture or litigation to block its execution. In September 2019, the Company amended its Credit Agreement to expressly permit formation of the joint venture and is exploring various alternatives under the Indenture governing the Senior Notes. At such time as control over the existing operations is exchanged, the Company will account for its interest in the combined operations at fair value, which could result in a significant loss. North Goonyella The Company’s North Goonyella Mine in Queensland, Australia experienced a fire in a portion of the mine during September 2018 and mining operations have been suspended since then. 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. During the first quarter of 2019, the Company completed segmenting of the mine into multiple zones to facilitate a phased reventilation and re-entry of the mine. The Company commenced reventilation of the first zone of the mine during the second quarter of 2019 and subsequently re-entered the area in the third quarter. Following these activities and a detailed review and assessment of North Goonyella, the Company determined that due to the time, cost and required regulatory approach to ventilate and re-enter the rest of the mine, the Company will not pursue attempts to access certain portions of the mine through existing mine workings, but instead will move to the southern panels. The Company is currently in discussions with the QMI regarding ventilation and re-entry of the second zone of the current mine configuration. In 2020, the Company is commencing a commercial process for North Goonyella in conjunction with the existing mine development. The process comes in response to expressions of interest from potential strategic partners and other producers. Commercial outcomes could include a strategic financial partner, joint venture structure or complete sale of North Goonyella. 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. As work progressed and more information became available, the Company recorded an additional $111.5 million in containment and idling costs and an additional provision of $83.2 million related to equipment losses during the year ended December 31, 2019. The combined provision includes $50.7 million for the estimated cost to replace leased equipment, $45.6 million related to the cost of Company-owned equipment, $39.7 million related to unrecoverable longwall panel development and $13.6 million of other charges, which represents the best estimate of loss based on the assessments made at December 31, 2019. In the event that no future mining occurs at the North Goonyella Mine or the Company is unable to find a commercial alternative, the Company may record additional charges for the remaining carrying value of the North Goonyella Mine of up to approximately $300 million. Incremental exposures above the aforementioned include take-or-pay obligations and other costs associated with idling or closing the mine. In March 2019, the Company entered into an insurance claim settlement agreement with its insurers and various re-insurers under a combined property damage and business interruption policy and recorded a $125 million insurance recovery, the maximum amount available under the policy above a $50 million deductible. The Company has collected the full amount of the recovery. On April 30, 2019, Peabody (Bowen) Pty Ltd entered into an option exercise and release agreement with Yancoal Technology Development Pty Ltd pursuant to which Peabody (Bowen) Pty Ltd exercised an option to acquire from Yancoal Technology Development Pty Ltd the longwall mining equipment used under license at the North Goonyella Mine for $54.2 million, which was consistent with what the Company recorded as a provision for equipment losses for the related impaired assets. Divestitures and Other Transactions The Company’s Kayenta Mine closed during August 2019 upon termination of its coal supply agreement with the Navajo Generating Station (NGS) in Arizona. The NGS was the sole customer of the Kayenta Mine and the coal supply agreement provided for consideration to the Company related to its post-mining obligations for retiree healthcare and reclamation costs. A cumulative portion of such consideration, $53.5 million, was held in trust and released to the Company upon termination. During the fourth quarter of 2019, the parties entered into a settlement agreement to finalize such consideration for an additional $78.5 million payable to the Company. Of this amount, $35.4 million was receivable at December 31, 2019 and $16.3 million of such receivable was collected in January 2020. 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 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. 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 had 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 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.

In December 2019, after receiving the requisite regulatory and permitting approvals, the Company formed an unincorporated joint venture 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 will proportionally consolidate the entity based upon its economic interest. Glencore will manage the mining operations of the joint venture (United Wambo Joint Venture).

Both parties contributed mining tenements and other assets upon formation. The Company accounted for its interest in the United Wambo Joint Venture at fair value and recognized a gain of $48.1 million, which was classified in “Gain on formation of United Wambo Joint Venture” in the accompanying consolidated statements of operations during the year ended December 31, 2019. The gain represents the difference between the fair value of the Company’s interest in the joint venture, $63.7 million, and the carrying value of the Company’s net assets contributed upon formation, $15.6 million. The fair value of the Company’s interest in the joint venture is based on applying the income and cost valuation methods to the combined mining tenements and includes a provision for the estimated fair value of related asset retirement obligations.

On June 18, 2019, the Company entered into a definitive implementation agreement (the Implementation Agreement) with Arch, to establish a joint venture that will combine the respective Powder River Basin and Colorado operations of Peabody and Arch. Pursuant to the terms of the Implementation Agreement, Peabody will hold a 66.5% economic interest in the joint venture and Arch will hold a 33.5% economic interest. The Company expects to proportionally consolidate the entity based upon its economic interest. Governance of the joint venture will be overseen by the joint venture’s board of managers, which will be comprised of Peabody and Arch representatives with voting powers proportionate with the companies’ economic interests, with the exception of certain specified matters which will require supermajority approval. Peabody will manage the operations of the joint venture, subject to the supervision of the joint venture’s board of managers.

Formation of the joint venture is subject to customary closing conditions, including the termination or expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, the receipt of certain other required regulatory approvals and the absence of injunctions or other legal restraints preventing the formation of the joint venture. The proposed joint venture is progressing through the U.S. Federal Trade Commission regulatory review process and the Company expects a decision in the first quarter, which would result in the clearance to form the joint venture or litigation to block its execution. In September 2019, the Company amended its Credit Agreement to expressly permit formation of the joint venture and is exploring various alternatives under the Indenture governing the Senior Notes. At such time as control over the existing operations is exchanged, the Company will account for its interest in the combined operations at fair value, which could result in a significant loss.

The Company’s North Goonyella Mine in Queensland, Australia experienced a fire in a portion of the mine during September 2018 and mining operations have been suspended since then. 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.

During the first quarter of 2019, the Company completed segmenting of the mine into multiple zones to facilitate a phased reventilation and re-entry of the mine. The Company commenced reventilation of the first zone of the mine during the second quarter of 2019 and subsequently re-entered the area in the third quarter. Following these activities and a detailed review and assessment of North Goonyella, the Company determined that due to the time, cost and required regulatory approach to ventilate and re-enter the rest of the mine, the Company will not pursue attempts to access certain portions of the mine through existing mine workings, but instead will move to the southern panels. The Company is currently in discussions with the QMI regarding ventilation and re-entry of the second zone of the current mine configuration. In 2020, the Company is commencing a commercial process for North Goonyella in conjunction with the existing mine development. The process comes in response to expressions of interest from potential strategic partners and other producers. Commercial outcomes could include a strategic financial partner, joint venture structure or complete sale of North Goonyella.

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. As work progressed and more information became available, the Company recorded an additional $111.5 million in containment and idling costs and an additional provision of $83.2 million related to equipment losses during the year ended December 31, 2019. The combined provision includes $50.7 million for the estimated cost to replace leased equipment, $45.6 million related to the cost of Company-owned equipment, $39.7 million related to unrecoverable longwall panel development and $13.6 million of other charges, which represents the best estimate of loss based on the assessments made at December 31, 2019.

In the event that no future mining occurs at the North Goonyella Mine or the Company is unable to find a commercial alternative, the Company may record additional charges for the remaining carrying value of the North Goonyella Mine of up to approximately $300 million. Incremental exposures above the aforementioned include take-or-pay obligations and other costs associated with idling or closing the mine.

In March 2019, the Company entered into an insurance claim settlement agreement with its insurers and various re-insurers under a combined property damage and business interruption policy and recorded a $125 million insurance recovery, the maximum amount available under the policy above a $50 million deductible. The Company has collected the full amount of the recovery.

On April 30, 2019, Peabody (Bowen) Pty Ltd entered into an option exercise and release agreement with Yancoal Technology Development Pty Ltd pursuant to which Peabody (Bowen) Pty Ltd exercised an option to acquire from Yancoal Technology Development Pty Ltd the longwall mining equipment used under license at the North Goonyella Mine for $54.2 million, which was consistent with what the Company recorded as a provision for equipment losses for the related impaired assets.

The Company’s Kayenta Mine closed during August 2019 upon termination of its coal supply agreement with the Navajo Generating Station (NGS) in Arizona. The NGS was the sole customer of the Kayenta Mine and the coal supply agreement provided for consideration to the Company related to its post-mining obligations for retiree healthcare and reclamation costs. A cumulative portion of such consideration, $53.5 million, was held in trust and released to the Company upon termination. During the fourth quarter of 2019, the parties entered into a settlement agreement to finalize such consideration for an additional $78.5 million payable to the Company. Of this amount, $35.4 million was receivable at December 31, 2019 and $16.3 million of such receivable was collected in January 2020.

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 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.

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 had 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 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.