Other Events	6 Months Ended
Other Events	Jun. 30, 2024
Other Events [Abstract]
Other Events	Other Events Wards Well Acquisition The Company entered into a definitive agreement dated October 26, 2023, to acquire the southern part of the Wards Well tenements (Wards Well) which are adjacent to the Company’s Centurion Mine in Queensland, Australia. The acquisition, which was accounted for as an asset acquisition, was completed on April 16, 2024. The acquired asset was measured at the cost of the acquisition based on the total consideration, allocated on the basis of relative fair value. The total consideration of $153.4 million, consisting of cash consideration of $134.4 million, cash transaction costs of $9.4 million and the non-cash settlement of existing receivables with the acquiree of $9.6 million, was recorded in “Property, plant, equipment and mine development, net” in the condensed consolidated balance sheets as of June 30, 2024. The agreement also includes an initial contingent royalty of up to $200 million. The royalty will only be payable once the Company has recovered its investment and development costs of Wards Well and if the average sales price achieved exceeds certain thresholds. No royalty is payable if the Company does not commence mining Wards Well. The Company will adjust the cost basis of the assets acquired if and when the contingent royalty is paid or becomes payable. Share Repurchases During the six months ended June 30, 2024, the Company repurchased approximately 3.2 million shares of its common stock for $80.5 million, including commission fees. No shares were repurchased during the three months ended June 30, 2024. The Company had accrued excise taxes of $4.0 million related to share repurchases, which were unpaid at June 30, 2024. The Company includes commission fees and excise taxes, as incurred, with the cost of treasury stock. At June 30, 2024, $569.6 million remained available under its share repurchase program. 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 six months ended June 30, 2023, the Company recorded a provision for loss of $5.0 million related to the tornado damage, which included $4.0 million for materials and supplies inventories and $1.0 million for buildings and equipment. During the three and six months ended June 30, 2024, the Company recorded $1.9 million and $3.7 million, respectively, for incremental repair costs related to the tornado damage. Shoal Creek 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. During the three and six months ended June 30, 2023, the Company recorded a provision for loss of $28.7 million related to the fire, which included $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 2023, 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. During June 2024, the Company reached a settlement with its insurers and various re-insurers and recognized a $109.5 million insurance recovery which the Company included in its results of operations for the three and six months ended June 30, 2024. During the six months ended June 30, 2024, the Company collected $5.6 million of the insurance recovery. Since this portion of the recovery related to equipment damage for which the Company previously recognized the provision for loss, the Company has classified the amount within the “Cash Flows From Investing Activities” section of the unaudited condensed consolidated statements of cash flows. The remaining $103.9 million of the insurance recovery was recorded as a receivable within “Accounts receivable, net” in the condensed consolidated balance sheets as of June 30, 2024. Port and Rail Capacity Assignment During the six months ended June 30, 2023, the Company entered into an agreement to assign the right to its excess port and rail capacity related to its Centurion 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 was payable in June 2024, subject to certain conditions. In connection with the transaction, the Company recorded revenue of $19.2 million during the six months ended June 30, 2023. In association with the completion of the Wards Well acquisition described above, the remaining receivable was settled as part of the consideration on April 16, 2024.