Other Events	9 Months Ended
Other Events	Sep. 30, 2019
Other Events [Abstract]
Other Events	Other Events 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 mining 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. 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 which is anticipated to conclude during the first half of 2020, and which would result in the clearance to form the joint venture or litigation to block its execution. The existing outstanding indebtedness of both Peabody and Arch limits significant transactions such as the joint venture, and accordingly, formation is subject to Peabody and Arch amending such outstanding indebtedness under agreeable terms. 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. 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. During the first quarter of 2019, the Company completed segmenting of the mine into multiple zones to facilitate a phased re-ventilation and re-entry of the mine. The Company commenced re-ventilation of the first zone of the mine during the second quarter of 2019 and subsequently re-entered the area in July 2019. Following these activities and a subsequent detailed assessment, the Company concluded during the fourth quarter of 2019 that due to the time, cost and required regulatory approach to ventilate and re-enter the entire mine, the Company will not pursue attempts to access certain portions of the mine through existing mine workings, but will instead move to the southern panels. 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 Mine and a provision of $66.4 million for expected equipment losses. The portion recorded during the three and nine months ended September 30, 2018 amounted to $9.0 million in containment and idling costs and a provision of $49.3 million for expected equipment losses. During the three and nine months ended September 30, 2019, the Company recorded an additional $29.3 million and $94.6 million, respectively, in containment and idling costs, and an additional provision of $24.7 million related to equipment losses was recorded during the nine months ended September 30, 2019 as more information became available. The combined provision includes $50.7 million for the estimated cost to replace leased equipment, $23.2 million related to the cost of Company-owned equipment and $17.2 million of other charges, which represents the best estimate of loss based on the assessments made at September 30, 2019. Given the revision in its approach to accessing the remaining reserves made during the fourth quarter of 2019, the Company recorded an additional provision for equipment losses of approximately $60 million, primarily related to unrecoverable longwall panel development, subsequent to September 30, 2019. 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 of up to approximately $272 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 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 unaudited condensed consolidated statements of operations for the three and nine months ended September 30, 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 unaudited condensed consolidated statements of operations for the nine months ended September 30, 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 unaudited condensed consolidated statements of operations for the nine months ended September 30, 2018. United Wambo Joint Venture with Glencore 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. Glencore will manage the operations of the joint venture. The joint venture is expected to be formed during 2019, subject to substantive contingencies for the requisite regulatory and permitting approvals. Mining tenements will be contributed at formation and open-cut operations will be transitioned at first scheduled coal delivery date of joint venture operations. The Company will account for the components of the transaction at fair value, which could result in a gain or loss. Asset Impairment and At-Risk Assets In addition to the provision for North Goonyella equipment losses described above, the Company recorded $20.0 million of asset impairment charges during the three and nine months ended September 30, 2019 related to the remaining probability-weighted discounted cash flows of its Wildcat Hills Underground Mine, which the Company has announced will likely close in the fourth quarter of 2019. No asset impairment charges were recorded during the three and nine months ended September 30, 2018. Due to the unobservable inputs within the modeling used to determine fair market values utilized in the Company's asset impairment analyses, such fair values would be considered Level 3 within the fair value hierarchy. The Company has identified certain assets with an aggregate carrying value of approximately $358 million at September 30, 2019 in its Midwestern U.S. Mining, Western U.S. Mining and Corporate and Other segments whose recoverability is most sensitive to coal pricing, cost pressures and customer concentration risk. The Company conducted a review of those assets for recoverability as of September 30, 2019 and determined that no further impairment charges were necessary as of that date.