Commitments and Contingencies	3 Months Ended
Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments Unconditional Purchase Obligations As of March 31, 2018, purchase commitments for capital expenditures were $190.1 million, all of which is obligated within the next three years, with $140.7 million obligated in the next year. There were no other material changes to the Company’s commitments from the information provided in Note 25. “Commitments and Contingencies” to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. Contingencies From time to time, the Company or its subsidiaries are involved in legal proceedings arising in the ordinary course of business or related to indemnities or historical operations. The Company believes it has recorded adequate reserves for these liabilities. The Company discusses its significant legal proceedings below, including ongoing proceedings and those that impacted the Company’s results of operations for the periods presented. Litigation Relating to the Chapter 11 Cases Ad Hoc Committee. A group of creditors (the Ad Hoc Committee) that held certain interests in the Company's prepetition indebtedness appealed the Bankruptcy Court's order confirming the Plan. On December 29, 2017, the United States District Court for the Eastern District of Missouri (the District Court) entered an order dismissing the Ad Hoc Committee's appeal, and, in the alternative, affirming the order confirming the Plan. On January 26, 2018, the Ad Hoc Committee appealed the District Court's order to the United States Court of Appeals for the Eighth Circuit (the Eighth Circuit). In its appeal, the Ad Hoc Committee does not ask the Eighth Circuit to reverse the order confirming the Plan. Instead, the Ad Hoc Committee asks the Eighth Circuit to award the Ad Hoc Committee members either unspecified damages or the right to buy an unspecified amount of Company stock at a discount. The Company does not believe the appeal is meritorious and will vigorously defend it. Litigation Relating to Continuing Operations Peabody Monto Coal Pty Ltd, Monto Coal 2 Pty Ltd and Peabody Energy Australia PCI Pty Ltd (PEA-PCI). In October 2007, a statement of claim was delivered to Peabody Monto Coal Pty Ltd, a wholly-owned subsidiary of PEA-PCI, that was then known as Macarthur Coal Limited, and Monto Coal 2 Pty Ltd, an equity accounted investee, from the minority interest holders in the Monto Coal Joint Venture, alleging that Monto Coal 2 Pty Ltd breached the Monto Coal Joint Venture Agreement and Peabody Monto Coal Pty Ltd breached the Monto Coal Management Agreement. Peabody Monto Coal Pty Ltd is the manager of the Monto Coal Joint Venture pursuant to the Management Agreement. Monto Coal 2 Pty Ltd holds a 51% interest in the Monto Coal Joint Venture. The plaintiffs are Sanrus Pty Ltd, Edge Developments Pty Ltd and H&J Enterprises (Qld) Pty Ltd. An additional statement of claim was delivered to PEA-PCI in November 2010 from the same minority interest holders in the Monto Coal Joint Venture, alleging that PEA-PCI induced Monto Coal 2 Pty Ltd and Peabody Monto Coal Pty Ltd to breach the Monto Coal Joint Venture Agreement and the Monto Coal Management Agreement, respectively. The plaintiffs later amended their claim to allege damages for lost opportunities to sell their joint venture interest. These actions, which are pending before the Supreme Court of Queensland, Australia, seek damages from the three defendants collectively of amounts ranging from $15.6 million Australian dollars to $1.8 billion Australian dollars, plus interest and costs. The defendants dispute the claims and are vigorously defending their positions. Orders have been made by the court relating to trial preparation steps, with the steps expected to be completed by the end of 2018. The current court order provides the parties will participate in mediation by the end of August 2018. The court also has indicated that it intends to set this matter for a 14 -16 week trial commencing February or March of 2019. Based on the Company’s evaluation of the issues and their potential impact, the amount of any future loss currently cannot be reasonably estimated. Berenergy Corporation. The Company has been in a legal dispute with Berenergy Corporation (Berenergy) regarding Berenergy’s access to certain of its underground oil deposits beneath the Company’s North Antelope Rochelle Mine and contiguous undisturbed areas. Berenergy contends the Company could be liable to Berenergy for the cost of certain special procedures and equipment required to access the secondary deposits remotely from outside the Company’s mine area, which has been estimated as $13.1 million by Berenergy. The Company believes that any claims related to this matter are without merit and constitute prepetition claims. The Company is currently seeking to resolve the underlying access conflict through the Bureau of Land Management (BLM), and believes that the likelihood of a material loss resulting from the matter is remote. County of San Mateo, County of Marin, City of Imperial Beach. The Company was named as a defendant, along with numerous other companies, in three nearly identical lawsuits. The lawsuits seek to hold a wide variety of companies that produce fossil fuels liable for the alleged impacts of the greenhouse gas emissions attributable to those fuels. The lawsuits primarily assert that the companies’ products have caused a sea level rise that is damaging the plaintiffs. The complaints specifically alleged that the defendants’ activities from 1965 to 2015 caused such damage. The Company filed a motion to enforce the Confirmation Order in the Bankruptcy Court because the Confirmation Order enjoins claims that arose before the effective date of the Plan. The motion to enforce was heard on October 5, 2017 and granted on October 24, 2017. The Bankruptcy Court ordered the plaintiffs to dismiss their lawsuits against the Company. On November 26, 2017, the plaintiffs appealed the Bankruptcy Court’s October 24, 2017 order to the U.S. District Court for the Eastern District of Missouri. On November 28, 2017, plaintiffs sought a stay pending appeal from the Bankruptcy Court, which was denied December 8, 2017. On December 19, 2017, the plaintiffs moved the U.S. District Court for the Eastern District of Missouri for a stay pending appeal. No decision from the District Court has been made on the request for a stay and the briefing on the appeal has been completed. The parties are waiting for a decision on the motion for stay and on the merits of the appeal. In the underlying cases pending in California, the District Court for the Northern District of California granted plaintiffs’ motion for remand and decided the cases should be heard in state court. The defendants appealed the order granting remand to the Ninth Circuit and sought a stay of the District Court decision pending completion of the Ninth Circuit appeal. The District Court for the Northern District of California granted defendants’ request for a stay pending completion of the Ninth Circuit appeal. 10th Circuit U.S. Bureau of Land Management Appeal. On September 15, 2017, the Tenth Circuit Court of Appeals reversed the District Court of Wyoming’s decision upholding BLM’s approval of four coal leases in the Powder River Basin. Two of the four leases relate to the Company’s North Antelope Rochelle Mine in Wyoming. There is no immediate impact on the Company’s leases as the Court of Appeals did not vacate the leases as part of its ruling. Rather, the Court of Appeals remanded the case back to the District Court with directions to order BLM to revise its environmental analysis. On November 27, 2017, the District Court ordered BLM to revise its environmental analysis. Plaintiffs then asked the court to order remedy briefing, which defendants and intervenors opposed because the District Court already addressed the proper remedy in its November 27, 2017 order. On April 2, 2018 the federal respondents filed a status report advising the District Court that they would conduct an environmental assessment to remedy the National Environmental Policy Act defect found by the Tenth Circuit, and that the draft environmental assessment would be completed and ready for public review and comment on or before June 30, 2018. On April 19, 2018 the court orally denied plaintiffs’ request for remedy briefing without prejudice. Plaintiffs may renew their request if BLM does not submit a draft environmental assessment by the end of July 2018. The Company’s operations will continue in the normal course during this period since the decision has no impact on mining at this time. The Company currently believes that its operations are unlikely to be materially impacted by this case, but the timing and magnitude of any impact on the Company’s future operations is not certain. Wilpinjong Extension Project (WEP). Wollar Progress Association has applied to the Land & Environment Court for a judicial review of the New South Wales Planning Assessment Commission’s decision to approve the WEP. The matter was heard by the court in early February 2018. However, a decision has not yet been ordered. In the interim, the Company’s Wilpinjong Mine continues to mine in accordance with its approvals. Central Arizona Water Conservation District (CAWCD). On May 1, 2018, the Company, along with the Hopi Tribe and the United Mine Workers of America, filed a lawsuit against the CAWCD. CAWCD operates, on behalf of the Bureau of Reclamation, the Central Arizona Project (CAP), an aqueduct system that brings water from the Colorado River to three counties in Arizona. CAWCD historically obtained most of CAP’s power requirements from the Navajo Generating Station (NGS), which is served by a single Peabody mine. NGS is owned by several private companies and one governmental entity. The non-governmental owners of NGS issued a statement that they do not currently intend to be the operators of the plant beyond December 2019. A number of potential investors have expressed interest in pursuing an ownership position in NGS. Recently, CAWCD made the decision to obtain CAP’s power requirements from sources other than NGS for 2020 and thereafter. The lawsuit seeks a determination that federal law requires CAWCD to obtain CAP’s power requirements from NGS. Other At times the Company becomes a party to other disputes, including those related to contract miner performance, claims, lawsuits, arbitration proceedings, regulatory investigations and administrative procedures in the ordinary course of business in the U.S., Australia and other countries where the Company does business. Based on current information, the Company believes that such other pending or threatened proceedings are likely to be resolved without a material adverse effect on its financial condition, results of operations or cash flows.

Commitments and Contingencies

Commitments

Unconditional Purchase Obligations

As of March 31, 2018, purchase commitments for capital expenditures were $190.1 million, all of which is obligated within the next three years, with $140.7 million obligated in the next year.

There were no other material changes to the Company’s commitments from the information provided in Note 25. “Commitments and Contingencies” to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017.

Contingencies

From time to time, the Company or its subsidiaries are involved in legal proceedings arising in the ordinary course of business or related to indemnities or historical operations. The Company believes it has recorded adequate reserves for these liabilities. The Company discusses its significant legal proceedings below, including ongoing proceedings and those that impacted the Company’s results of operations for the periods presented.

Litigation Relating to the Chapter 11 Cases

Ad Hoc Committee. A group of creditors (the Ad Hoc Committee) that held certain interests in the Company's prepetition indebtedness appealed the Bankruptcy Court's order confirming the Plan. On December 29, 2017, the United States District Court for the Eastern District of Missouri (the District Court) entered an order dismissing the Ad Hoc Committee's appeal, and, in the alternative, affirming the order confirming the Plan. On January 26, 2018, the Ad Hoc Committee appealed the District Court's order to the United States Court of Appeals for the Eighth Circuit (the Eighth Circuit). In its appeal, the Ad Hoc Committee does not ask the Eighth Circuit to reverse the order confirming the Plan. Instead, the Ad Hoc Committee asks the Eighth Circuit to award the Ad Hoc Committee members either unspecified damages or the right to buy an unspecified amount of Company stock at a discount. The Company does not believe the appeal is meritorious and will vigorously defend it.

Litigation Relating to Continuing Operations

Peabody Monto Coal Pty Ltd, Monto Coal 2 Pty Ltd and Peabody Energy Australia PCI Pty Ltd (PEA-PCI). In October 2007, a statement of claim was delivered to Peabody Monto Coal Pty Ltd, a wholly-owned subsidiary of PEA-PCI, that was then known as Macarthur Coal Limited, and Monto Coal 2 Pty Ltd, an equity accounted investee, from the minority interest holders in the Monto Coal Joint Venture, alleging that Monto Coal 2 Pty Ltd breached the Monto Coal Joint Venture Agreement and Peabody Monto Coal Pty Ltd breached the Monto Coal Management Agreement. Peabody Monto Coal Pty Ltd is the manager of the Monto Coal Joint Venture pursuant to the Management Agreement. Monto Coal 2 Pty Ltd holds a 51% interest in the Monto Coal Joint Venture. The plaintiffs are Sanrus Pty Ltd, Edge Developments Pty Ltd and H&J Enterprises (Qld) Pty Ltd. An additional statement of claim was delivered to PEA-PCI in November 2010 from the same minority interest holders in the Monto Coal Joint Venture, alleging that PEA-PCI induced Monto Coal 2 Pty Ltd and Peabody Monto Coal Pty Ltd to breach the Monto Coal Joint Venture Agreement and the Monto Coal Management Agreement, respectively. The plaintiffs later amended their claim to allege damages for lost opportunities to sell their joint venture interest. These actions, which are pending before the Supreme Court of Queensland, Australia, seek damages from the three defendants collectively of amounts ranging from $15.6 million Australian dollars to $1.8 billion Australian dollars, plus interest and costs. The defendants dispute the claims and are vigorously defending their positions. Orders have been made by the court relating to trial preparation steps, with the steps expected to be completed by the end of 2018. The current court order provides the parties will participate in mediation by the end of August 2018. The court also has indicated that it intends to set this matter for a 14 -16 week trial commencing February or March of 2019. Based on the Company’s evaluation of the issues and their potential impact, the amount of any future loss currently cannot be reasonably estimated.

Berenergy Corporation. The Company has been in a legal dispute with Berenergy Corporation (Berenergy) regarding Berenergy’s access to certain of its underground oil deposits beneath the Company’s North Antelope Rochelle Mine and contiguous undisturbed areas. Berenergy contends the Company could be liable to Berenergy for the cost of certain special procedures and equipment required to access the secondary deposits remotely from outside the Company’s mine area, which has been estimated as $13.1 million by Berenergy. The Company believes that any claims related to this matter are without merit and constitute prepetition claims. The Company is currently seeking to resolve the underlying access conflict through the Bureau of Land Management (BLM), and believes that the likelihood of a material loss resulting from the matter is remote.

County of San Mateo, County of Marin, City of Imperial Beach. The Company was named as a defendant, along with numerous other companies, in three nearly identical lawsuits. The lawsuits seek to hold a wide variety of companies that produce fossil fuels liable for the alleged impacts of the greenhouse gas emissions attributable to those fuels. The lawsuits primarily assert that the companies’ products have caused a sea level rise that is damaging the plaintiffs. The complaints specifically alleged that the defendants’ activities from 1965 to 2015 caused such damage. The Company filed a motion to enforce the Confirmation Order in the Bankruptcy Court because the Confirmation Order enjoins claims that arose before the effective date of the Plan. The motion to enforce was heard on October 5, 2017 and granted on October 24, 2017. The Bankruptcy Court ordered the plaintiffs to dismiss their lawsuits against the Company. On November 26, 2017, the plaintiffs appealed the Bankruptcy Court’s October 24, 2017 order to the U.S. District Court for the Eastern District of Missouri. On November 28, 2017, plaintiffs sought a stay pending appeal from the Bankruptcy Court, which was denied December 8, 2017. On December 19, 2017, the plaintiffs moved the U.S. District Court for the Eastern District of Missouri for a stay pending appeal. No decision from the District Court has been made on the request for a stay and the briefing on the appeal has been completed. The parties are waiting for a decision on the motion for stay and on the merits of the appeal. In the underlying cases pending in California, the District Court for the Northern District of California granted plaintiffs’ motion for remand and decided the cases should be heard in state court. The defendants appealed the order granting remand to the Ninth Circuit and sought a stay of the District Court decision pending completion of the Ninth Circuit appeal. The District Court for the Northern District of California granted defendants’ request for a stay pending completion of the Ninth Circuit appeal.

10th Circuit U.S. Bureau of Land Management Appeal. On September 15, 2017, the Tenth Circuit Court of Appeals reversed the District Court of Wyoming’s decision upholding BLM’s approval of four coal leases in the Powder River Basin. Two of the four leases relate to the Company’s North Antelope Rochelle Mine in Wyoming. There is no immediate impact on the Company’s leases as the Court of Appeals did not vacate the leases as part of its ruling. Rather, the Court of Appeals remanded the case back to the District Court with directions to order BLM to revise its environmental analysis. On November 27, 2017, the District Court ordered BLM to revise its environmental analysis. Plaintiffs then asked the court to order remedy briefing, which defendants and intervenors opposed because the District Court already addressed the proper remedy in its November 27, 2017 order. On April 2, 2018 the federal respondents filed a status report advising the District Court that they would conduct an environmental assessment to remedy the National Environmental Policy Act defect found by the Tenth Circuit, and that the draft environmental assessment would be completed and ready for public review and comment on or before June 30, 2018. On April 19, 2018 the court orally denied plaintiffs’ request for remedy briefing without prejudice. Plaintiffs may renew their request if BLM does not submit a draft environmental assessment by the end of July 2018. The Company’s operations will continue in the normal course during this period since the decision has no impact on mining at this time. The Company currently believes that its operations are unlikely to be materially impacted by this case, but the timing and magnitude of any impact on the Company’s future operations is not certain.

Wilpinjong Extension Project (WEP). Wollar Progress Association has applied to the Land & Environment Court for a judicial review of the New South Wales Planning Assessment Commission’s decision to approve the WEP. The matter was heard by the court in early February 2018. However, a decision has not yet been ordered. In the interim, the Company’s Wilpinjong Mine continues to mine in accordance with its approvals.

Central Arizona Water Conservation District (CAWCD). On May 1, 2018, the Company, along with the Hopi Tribe and the United Mine Workers of America, filed a lawsuit against the CAWCD. CAWCD operates, on behalf of the Bureau of Reclamation, the Central Arizona Project (CAP), an aqueduct system that brings water from the Colorado River to three counties in Arizona. CAWCD historically obtained most of CAP’s power requirements from the Navajo Generating Station (NGS), which is served by a single Peabody mine. NGS is owned by several private companies and one governmental entity. The non-governmental owners of NGS issued a statement that they do not currently intend to be the operators of the plant beyond December 2019. A number of potential investors have expressed interest in pursuing an ownership position in NGS. Recently, CAWCD made the decision to obtain CAP’s power requirements from sources other than NGS for 2020 and thereafter. The lawsuit seeks a determination that federal law requires CAWCD to obtain CAP’s power requirements from NGS.

Other

At times the Company becomes a party to other disputes, including those related to contract miner performance, claims, lawsuits, arbitration proceedings, regulatory investigations and administrative procedures in the ordinary course of business in the U.S., Australia and other countries where the Company does business. Based on current information, the Company believes that such other pending or threatened proceedings are likely to be resolved without a material adverse effect on its financial condition, results of operations or cash flows.