Commitments and Contingencies	3 Months Ended
Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments Unconditional Purchase Obligations As of March 31, 2014, purchase commitments for capital expenditures were $50.4 million, all of which are obligated within the next 12 months. There were no other material changes to the Company’s commitments from the information provided in Note 24 to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013. 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 and that there is no individual case pending that is likely to have a material adverse effect on the Company’s financial condition, results of operations or cash flows. 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 Continuing Operations Monto Coal Pty Limited, Monto Coal 2 Pty Ltd Limited and Macarthur Coal Limited. In October 2007, a statement of claim was delivered to Monto Coal Pty Ltd, a wholly owned subsidiary of PEA-PCI, then 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 Monto Coal Pty Ltd breached the Monto Coal Management Agreement. 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 Monto Coal Pty Ltd to breach the Monto Coal Joint Venture Agreement and the Monto Coal Management Agreement, respectively. These actions, which are pending before the Supreme Court of Queensland, Australia, seek damages from the three defendants collectively of $1,193.2 million Australian dollars, plus interest and costs. The defendants dispute the claims and are vigorously defending their positions. Based on the Company's evaluation of the issues and their potential impact, the amount of any future loss cannot be reasonably estimated. However, based on current information, the Company believes these claims are likely to be finalized without a material adverse effect on its financial condition, results of operations or cash flows. Sumiseki Materials Co Ltd. In 2010, the Class B shareholder (noncontrolling interest holder) in Wambo Coal Pty Ltd (Wambo), an Australian subsidiary of the Company, filed a lawsuit in the Supreme Court of Wales, Australia, against Wambo alleging the Class B shareholder was entitled to certain dividend payments from Wambo (subject to limited exceptions) and requested payment of those dividends for periods from 2009 to 2012. On March 25, 2013, the Supreme Court issued a judgment in favor of the plaintiff's position that the Class B shareholder was entitled to dividend payments (subject to limited exceptions), thus requiring Wambo to pay dividends to the Class B shareholder for the periods in question. The Supreme Court issued finalized orders on May 3, 2013, including the final calculation of amounts due for dividends during the periods from 2009 to 2012 totaling $29.0 million plus interest of $5.6 million. Amounts of the finalized orders are presented in U.S. dollars at foreign currency exchange rates in effect at March 31, 2014. Wambo has filed an appeal of the Supreme Court's decision, and has posted the requisite security of $48.4 million, which amount includes the calculated potential amounts due for 2013, with the court in the form of cash payment into an interest bearing trust account jointly operated by the parties. Because the Supreme Court's order allows for the substitution of that posted cash payment with a bank guarantee from an Australian bank or another form of acceptable security, those funds remain readily available to the Company and have therefore been reflected in "Cash and cash equivalents" in the unaudited condensed consolidated balance sheet as of March 31, 2014. Based on information currently available, the Company believes that its subsidiary should be successful in the appeals process, and therefore, has not declared any dividends and continues to reflect the previously allocated earnings to "Noncontrolling interests" in the unaudited condensed consolidated balance sheet as of March 31, 2014. If the Supreme Court's ruling is upheld, the Company believes the claims are likely to be finalized without a material adverse effect on its financial condition, results of operations or cash flows. Eagle Mining, LLC Arbitration. On May 3, 2013, Eagle Mining, LLC (Eagle) filed an arbitration demand against a Company subsidiary under a contract mining agreement, asserting various claims for damages. An arbitration hearing was held in January 2014 before a single arbitrator. On March 18, 2014, the arbitrator awarded Eagle damages on some of its claims in the total amount of $23.4 million. In December 2013, prior to the arbitration hearing, the Company subsidiary established a reserve in the amount of $7.8 million, which amount represented the low end of the Company's previous estimated range of loss associated with the matter. The difference between the Company’s reserve amount and the amount of the award was primarily due to damages that were awarded on one of the claims at the high end of the Company’s previous estimated range of loss, and that were awarded on another claim for which the Company initially determined the probability of loss to be remote. As a result of the damages awarded to Eagle in arbitration, the Company recorded an additional charge of $15.6 million in "Operating costs and expenses" in the unaudited condensed consolidated statement of operations for the three months ended March 31, 2014. On April 18, 2014, the Company subsidiary filed a petition to partially vacate and modify the arbitration award in the United States District Court for the Southern District of West Virginia, Charleston Division. Claims, Litigation and Settlements Relating to Indemnities or Historical Operations Environmental Claims and Litigation Claims Arising From Historical, Non-Coal Producing Operations. Gold Fields Mining, LLC (Gold Fields) is a dormant, non-coal producing entity that was previously managed and owned by Hanson plc, the Company's predecessor owner. In a February 1997 spin-off, Hanson plc transferred ownership of Gold Fields to the Company, despite the fact that Gold Fields had no ongoing operations and the Company had no prior involvement in its past operations. Gold Fields is currently one of the Company's subsidiaries. The Company indemnified TXU Group with respect to certain claims relating to the historical operations of a former affiliate of Gold Fields. Environmental claims for remediation, past costs, future costs, and/or natural resource damages have been asserted against Gold Fields related to historical activities of Gold Fields or a former affiliate. Gold Fields or the former affiliate has been named a potentially responsible party (PRP) at five national priority list sites based on the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). CERCLA claims were asserted at 13 additional sites, bringing the total to 18, which have since been reduced to eight by completion of work, transfer or regulatory inactivity. The number of CERCLA sites alone is not a relevant measure of liability because the nature and extent of environmental concerns and costs varies by site, as does the estimated share of responsibility relative to other PRPs for Gold Fields or the former affiliate. Undiscounted liabilities for environmental cleanup-related costs for all of the sites noted above were $62.5 million as of March 31, 2014 and $63.8 million as of December 31, 2013, $17.0 million and $18.3 million of which was reflected as a current liability, respectively. These amounts represent those costs that the Company believes are probable and reasonably estimable. Significant uncertainty exists as to whether claims will be pursued against Gold Fields or the former affiliate in all cases, and where they are pursued, the amount and timing of the eventual costs and liabilities, which could be greater or less than the liabilities recorded in the condensed consolidated balance sheets. Changes to cost estimates associated with a particular site can occur for many reasons, including, but not limited to, the gathering of additional information at the site, the completion of the remedial design phase of the CERCLA remediation process, changes in anticipated remediation standards or labor and material costs or the reaching of a settlement agreement or consent order by the parties at the site. Based on the Company's evaluation of the issues and their potential impact, the total amount of any future loss cannot be reasonably estimated. However, based on current information, the Company believes these claims are likely to be resolved without a material adverse effect on its financial condition, results of operations or cash flows. Settlement Agreement with Patriot and the UMWA In 2012, Patriot Coal Corporation and certain of its wholly owned subsidiaries (Patriot) filed voluntary petitions for reorganization under Chapter 11 of the U.S. Bankruptcy Code. In 2013, the Company entered into a definitive settlement agreement with Patriot and the United Mine Workers of America (UMWA), on behalf of itself, its represented Patriot employees and its represented Patriot retirees, to resolve all disputed issues related to Patriot’s bankruptcy. In connection with the settlement agreement with Patriot and the UMWA, which became effective on December 18, 2013, the Company is required to provide total payments of $310 million, payable over four years through 2017, to partially fund the newly established voluntary employee beneficiary association (VEBA) and settle all Patriot and UMWA claims involving the Patriot bankruptcy. Those payments included an initial payment of $90 million made in January 2014, comprised of $70 million paid to Patriot and $20 million paid to the VEBA, and subsequent payments of $75 million in 2015, $75 million in 2016 and $70 million in 2017 to be paid to the VEBA. Other In June 2007, the New York Office of the Attorney General (NYAG) served a letter and subpoena on the Company, seeking information and documents relating to the Company's disclosure to investors of risks associated with possible climate change and related legislation and regulations. The Company believes it has made full and proper disclosure of these potential risks. In late 2013, the NYAG submitted a letter to the Company requesting additional information and documents and the Company is in the process of complying with that request. In January 2013, the Securities and Exchange Commission (SEC) staff served a subpoena on the Company seeking information and documents relating to the development of Prairie State Energy Campus, a 1,600 megawatt coal-fueled electricity generation plant and adjacent coal mine in Illinois in which the Company owns a 5.06% undivided interest. The Company cooperated with the SEC's investigation and has not received any related communication from the SEC since August 2013. At times the Company becomes a party to other disputes, including those related to contract miner performance; claims; lawsuits; arbitration proceedings; 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, 2014, purchase commitments for capital expenditures were $50.4 million, all of which are obligated within the next 12 months.

There were no other material changes to the Company’s commitments from the information provided in Note 24 to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013.

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 and that there is no individual case pending that is likely to have a material adverse effect on the Company’s financial condition, results of operations or cash flows. 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 Continuing Operations

Monto Coal Pty Limited, Monto Coal 2 Pty Ltd Limited and Macarthur Coal Limited. In October 2007, a statement of claim was delivered to Monto Coal Pty Ltd, a wholly owned subsidiary of PEA-PCI, then 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 Monto Coal Pty Ltd breached the Monto Coal Management Agreement. 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 Monto Coal Pty Ltd to breach the Monto Coal Joint Venture Agreement and the Monto Coal Management Agreement, respectively. These actions, which are pending before the Supreme Court of Queensland, Australia, seek damages from the three defendants collectively of $1,193.2 million Australian dollars, plus interest and costs. The defendants dispute the claims and are vigorously defending their positions. Based on the Company's evaluation of the issues and their potential impact, the amount of any future loss cannot be reasonably estimated. However, based on current information, the Company believes these claims are likely to be finalized without a material adverse effect on its financial condition, results of operations or cash flows.

Sumiseki Materials Co Ltd. In 2010, the Class B shareholder (noncontrolling interest holder) in Wambo Coal Pty Ltd (Wambo), an Australian subsidiary of the Company, filed a lawsuit in the Supreme Court of Wales, Australia, against Wambo alleging the Class B shareholder was entitled to certain dividend payments from Wambo (subject to limited exceptions) and requested payment of those dividends for periods from 2009 to 2012.

On March 25, 2013, the Supreme Court issued a judgment in favor of the plaintiff's position that the Class B shareholder was entitled to dividend payments (subject to limited exceptions), thus requiring Wambo to pay dividends to the Class B shareholder for the periods in question. The Supreme Court issued finalized orders on May 3, 2013, including the final calculation of amounts due for dividends during the periods from 2009 to 2012 totaling $29.0 million plus interest of $5.6 million. Amounts of the finalized orders are presented in U.S. dollars at foreign currency exchange rates in effect at March 31, 2014.

Wambo has filed an appeal of the Supreme Court's decision, and has posted the requisite security of $48.4 million, which amount includes the calculated potential amounts due for 2013, with the court in the form of cash payment into an interest bearing trust account jointly operated by the parties. Because the Supreme Court's order allows for the substitution of that posted cash payment with a bank guarantee from an Australian bank or another form of acceptable security, those funds remain readily available to the Company and have therefore been reflected in "Cash and cash equivalents" in the unaudited condensed consolidated balance sheet as of March 31, 2014. Based on information currently available, the Company believes that its subsidiary should be successful in the appeals process, and therefore, has not declared any dividends and continues to reflect the previously allocated earnings to "Noncontrolling interests" in the unaudited condensed consolidated balance sheet as of March 31, 2014. If the Supreme Court's ruling is upheld, the Company believes the claims are likely to be finalized without a material adverse effect on its financial condition, results of operations or cash flows.

Eagle Mining, LLC Arbitration. On May 3, 2013, Eagle Mining, LLC (Eagle) filed an arbitration demand against a Company subsidiary under a contract mining agreement, asserting various claims for damages. An arbitration hearing was held in January 2014 before a single arbitrator. On March 18, 2014, the arbitrator awarded Eagle damages on some of its claims in the total amount of $23.4 million. In December 2013, prior to the arbitration hearing, the Company subsidiary established a reserve in the amount of $7.8 million, which amount represented the low end of the Company's previous estimated range of loss associated with the matter. The difference between the Company’s reserve amount and the amount of the award was primarily due to damages that were awarded on one of the claims at the high end of the Company’s previous estimated range of loss, and that were awarded on another claim for which the Company initially determined the probability of loss to be remote. As a result of the damages awarded to Eagle in arbitration, the Company recorded an additional charge of $15.6 million in "Operating costs and expenses" in the unaudited condensed consolidated statement of operations for the three months ended March 31, 2014. On April 18, 2014, the Company subsidiary filed a petition to partially vacate and modify the arbitration award in the United States District Court for the Southern District of West Virginia, Charleston Division.

Claims, Litigation and Settlements Relating to Indemnities or Historical Operations

Environmental Claims and Litigation

Claims Arising From Historical, Non-Coal Producing Operations. Gold Fields Mining, LLC (Gold Fields) is a dormant, non-coal producing entity that was previously managed and owned by Hanson plc, the Company's predecessor owner. In a February 1997 spin-off, Hanson plc transferred ownership of Gold Fields to the Company, despite the fact that Gold Fields had no ongoing operations and the Company had no prior involvement in its past operations. Gold Fields is currently one of the Company's subsidiaries. The Company indemnified TXU Group with respect to certain claims relating to the historical operations of a former affiliate of Gold Fields.

Environmental claims for remediation, past costs, future costs, and/or natural resource damages have been asserted against Gold Fields related to historical activities of Gold Fields or a former affiliate. Gold Fields or the former affiliate has been named a potentially responsible party (PRP) at five national priority list sites based on the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). CERCLA claims were asserted at 13 additional sites, bringing the total to 18, which have since been reduced to eight by completion of work, transfer or regulatory inactivity. The number of CERCLA sites alone is not a relevant measure of liability because the nature and extent of environmental concerns and costs varies by site, as does the estimated share of responsibility relative to other PRPs for Gold Fields or the former affiliate.

Undiscounted liabilities for environmental cleanup-related costs for all of the sites noted above were $62.5 million as of March 31, 2014 and $63.8 million as of December 31, 2013, $17.0 million and $18.3 million of which was reflected as a current liability, respectively. These amounts represent those costs that the Company believes are probable and reasonably estimable.

Significant uncertainty exists as to whether claims will be pursued against Gold Fields or the former affiliate in all cases, and where they are pursued, the amount and timing of the eventual costs and liabilities, which could be greater or less than the liabilities recorded in the condensed consolidated balance sheets. Changes to cost estimates associated with a particular site can occur for many reasons, including, but not limited to, the gathering of additional information at the site, the completion of the remedial design phase of the CERCLA remediation process, changes in anticipated remediation standards or labor and material costs or the reaching of a settlement agreement or consent order by the parties at the site. Based on the Company's evaluation of the issues and their potential impact, the total amount of any future loss cannot be reasonably estimated. However, based on current information, the Company believes these claims are likely to be resolved without a material adverse effect on its financial condition, results of operations or cash flows.

Settlement Agreement with Patriot and the UMWA

In 2012, Patriot Coal Corporation and certain of its wholly owned subsidiaries (Patriot) filed voluntary petitions for reorganization under Chapter 11 of the U.S. Bankruptcy Code. In 2013, the Company entered into a definitive settlement agreement with Patriot and the United Mine Workers of America (UMWA), on behalf of itself, its represented Patriot employees and its represented Patriot retirees, to resolve all disputed issues related to Patriot’s bankruptcy.

In connection with the settlement agreement with Patriot and the UMWA, which became effective on December 18, 2013, the Company is required to provide total payments of $310 million, payable over four years through 2017, to partially fund the newly established voluntary employee beneficiary association (VEBA) and settle all Patriot and UMWA claims involving the Patriot bankruptcy. Those payments included an initial payment of $90 million made in January 2014, comprised of $70 million paid to Patriot and $20 million paid to the VEBA, and subsequent payments of $75 million in 2015, $75 million in 2016 and $70 million in 2017 to be paid to the VEBA.

Other

In June 2007, the New York Office of the Attorney General (NYAG) served a letter and subpoena on the Company, seeking information and documents relating to the Company's disclosure to investors of risks associated with possible climate change and related legislation and regulations. The Company believes it has made full and proper disclosure of these potential risks. In late 2013, the NYAG submitted a letter to the Company requesting additional information and documents and the Company is in the process of complying with that request.

In January 2013, the Securities and Exchange Commission (SEC) staff served a subpoena on the Company seeking information and documents relating to the development of Prairie State Energy Campus, a 1,600 megawatt coal-fueled electricity generation plant and adjacent coal mine in Illinois in which the Company owns a 5.06% undivided interest. The Company cooperated with the SEC's investigation and has not received any related communication from the SEC since August 2013.

At times the Company becomes a party to other disputes, including those related to contract miner performance; claims; lawsuits; arbitration proceedings; 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.