Other Events	9 Months Ended
Other Events	Sep. 30, 2023
Other Events [Abstract]
Other Events	Other Events Coal Deposit Acquisition The Company entered into a definitive agreement dated October 26, 2023, with Stanmore SMC Pty Ltd (Stanmore) to acquire the southern part of Stanmore’s Wards Well tenements (Wards Well area) which are adjacent to the Company’s North Goonyella Mine in Queensland, Australia. The acquisition terms include cash consideration of $136 million and a contingent royalty of up to $200 million. The royalty will only be payable once the Company has recovered its investment and development costs of the Wards Well area and if the average sales price achieved exceeds certain thresholds. No royalty is payable if the Company does not commence mining in the Wards Well area. Completion of the transaction is subject to the satisfaction of certain conditions, including regulatory approvals. Share Repurchases During the three and nine months ended September 30, 2023, the Company repurchased approximately 3.7 million shares and 12.6 million shares, respectively, of its common stock for $82.4 million and $266.6 million, respectively, including commission fees. Of this amount, $2.6 million related to repurchases which settled subsequent to September 30, 2023. As of September 30, 2023, the Company had accrued excise taxes of $2.5 million related to the repurchases, which were unpaid at September 30, 2023. The Company includes commission fees and excise taxes, as incurred, with the cost of treasury stock. At September 30, 2023, $733.6 million remained available under its share repurchase program. From October 1, 2023 through October 27, 2023, the Company repurchased an additional 1.1 million shares for $27.3 million. North Antelope Rochelle Mine Tornado On June 23, 2023, the Company’s North Antelope Rochelle Mine sustained damage from a tornado which led to a temporary suspension of operations. The mine resumed operations on June 25, 2023. During the three and nine months ended September 30, 2023, the Company recorded a provision for loss of $3.3 million and $8.3 million, respectively, related to the tornado damage. The combined provision includes $4.0 million for materials and supplies inventories, $1.0 million for buildings and equipment and $3.3 million for incremental repair costs. The Company anticipates that incremental repair costs will continue to be recorded in future periods. Shoal Creek Incident On March 29, 2023, the Company’s Shoal Creek Mine experienced a fire involving void fill material utilized to stabilize the roof structure of the mine. On June 20, 2023, the Company announced that the Shoal Creek Mine, in coordination with the Mine Safety and Health Administration, had safely completed localized sealing of the affected area of the mine. Development coal production has been resumed in a new area of the mine. During the nine months ended September 30, 2023, the Company recorded a provision for loss of $28.7 million related to the fire. The provision includes $17.8 million related to longwall development and other costs and $10.9 million for equipment deemed inoperable within the affected area of the mine. In October, the Company filed an insurance claim against applicable insurance policies with combined business interruption and property loss limits of $125 million above a $50 million deductible. Port and Rail Capacity Assignment During the nine months ended September 30, 2023, the Company entered into an agreement to assign the right to its excess port and rail capacity related to its North Goonyella Mine to an unrelated party in exchange for $30.0 million Australian dollars. Half of such amount was received by the Company upon entry into the agreement, and half is payable in June 2024, subject to certain conditions. In connection with the transaction, the Company recorded revenue of $19.2 million during the nine months ended September 30, 2023 and had a discounted receivable of $9.4 million included in “Accounts receivable, net” as of September 30, 2023.