Description of the Business	12 Months Ended
Description of the Business	Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of the Business	Description of the Business Background and Nature of Operations Arcadium Lithium plc ("Arcadium", "Arcadium Lithium", "we", "us", "Company" or "our") is a public limited company incorporated under the laws of the Bailiwick of Jersey. On January 4, 2024, Arcadium Lithium completed the previously announced Allkem Livent Merger by which Livent Corporation, a Delaware corporation ("Livent"), and Allkem Limited, an Australian company limited by shares ("Allkem"), became wholly owned subsidiaries of Arcadium Lithium. On January 4, 2024, the Company's shares started trading on the New York Stock Exchange under the trading symbol ALTM. See Note 4, Allkem Livent Merger for further details. While Arcadium Lithium is a newly formed company from the merger of Allkem and Livent, our company has a rich heritage of innovation and a long, proven history of producing performance lithium compounds in a safe and sustainable manner. We are vertically integrated, with a global footprint and industry-leading end-to-end capabilities across lithium production including hard-rock mining, conventional pond-based brine extraction, direct lithium brine extraction and lithium chemicals manufacturing. Our lithium asset portfolio, consisting of both operating assets and development projects, provides us with global reach, scale, and product flexibility. Today we have operating resources in Argentina and Australia and downstream conversion assets in the U.S., China, Japan, and the U.K. We also have multiple development stage projects in Argentina (greenfield and brownfield) and Canada (greenfield) that will in time allow us to increase production capabilities and meet the future needs of customers around the world. In the U.S., we operate the only integrated mine-to-metal production facility in the Western Hemisphere for high purity lithium metal, a core component of next generation battery technologies. We manufacture a wide range of lithium products, including battery-grade lithium hydroxide, battery-grade lithium carbonate, spodumene, and other specialty chemicals such as butyllithium and high purity lithium metal. Our products are used in various performance applications, including lithium-based batteries, specialty polymers and pharmaceutical products and chemical synthesis applications. Pending Rio Tinto Transaction On October 9, 2024, Arcadium Lithium entered into the Transaction Agreement (the "Rio Tinto Transaction Agreement") with Rio Tinto Western Holdings Limited, a private limited company incorporated under the laws of England & Wales ("Parent"), and Rio Tinto BM Subsidiary Limited, a private limited company incorporated under the laws of England & Wales ("Buyer"). The Rio Tinto Transaction Agreement provides that pursuant to a scheme of arrangement (the "Scheme") under the Companies (Jersey) Law 1991, at the effective time of the Scheme, all of the ordinary shares, par value $1.00 per share, of the Company (the "Company Shares"), including the Company Shares represented by CHESS depositary interests issued by the Company and listed on the securities exchange operated by ASX Limited, then outstanding will be transferred from the shareholders of the Company to Buyer (or an affiliate of Buyer) in exchange for the right to receive an amount in cash, without interest, equal to $5.85 per Company Share (the "Rio Tinto Transaction"). If the Rio Tinto Transaction is consummated, the Company’s ordinary shares will be delisted from the New York Stock Exchange and the Company’s registration under the Exchange Act of 1934, as amended, will be terminated as promptly as practicable after the effective time of the Rio Tinto Transaction, and the quotation on the Australian Securities Exchange Ltd of the CHESS depositary interests issued by the Company will be suspended immediately prior to the effective time of the Rio Tinto Transaction. The closing of the Rio Tinto Transaction is subject to customary closing conditions under the Rio Tinto Transaction Agreement, including, among others: the approval of the Scheme by the Company’s shareholders (which has been obtained); all applicable governmental consents under specified antitrust and investment screening laws having been obtained and remaining in full force and effect and all applicable waiting periods having expired, lapsed or been terminated (as applicable) (which consents have been obtained and applicable waiting periods expired); no governmental entity of a competent jurisdiction having issued any order that is in effect and restrains, enjoins or otherwise prohibits the consummation of the Rio Tinto Transaction and no governmental entity having jurisdiction over any party having adopted any law that is in effect and makes consummation of the Rio Tinto Transaction illegal or otherwise prohibited; the representations and warranties of each of the Company and Parent being true and correct to the extent required by, and subject to the applicable materiality standards set forth in, the Rio Tinto Transaction Agreement; each of the Company, Parent and Buyer having in all material respects performed the obligations and complied with the covenants required to be performed or complied with by it under the Rio Tinto Transaction Agreement; and there having been no material adverse effect (as defined in the Rio Tinto Transaction Agreement). The timing surrounding whether these conditions will be satisfied or waived, if at all, is uncertain. Additionally, other events could intervene to delay or result in the failure to close the Rio Tinto Transaction. The Rio Tinto Transaction is currently expected to close shortly after the sanction hearing for the Royal Court of Jersey set on March 5, 2025, subject to satisfaction of the closing conditions. If the Rio Tinto Transaction has not closed by October 9, 2025 (subject to extension until April 9, 2026 in order to obtain antitrust or investment screening law or other regulatory approvals), either the Company or Parent may choose to terminate the Rio Tinto Transaction Agreement. The Rio Tinto Transaction Agreement provides that, if the Rio Tinto Transaction Agreement is terminated, the Company will pay a $200 million termination fee to Rio Tinto in the case of certain events described in the Rio Tinto Transaction Agreement, including if the Rio Tinto Transaction Agreement is terminated in certain circumstances and the Company enters into an agreement for an alternative transaction within twelve months of such termination. However, this right to terminate the Rio Tinto Transaction Agreement will not be available to the Company or Parent if such party has materially breached the Rio Tinto Transaction Agreement and the breach is the principal cause of the failure of the closing to have occurred prior to such date. The Company or Parent may elect to terminate the Rio Tinto Transaction Agreement in certain other circumstances, including if the Company’s shareholders fail to approve the Rio Tinto Transaction at the shareholder meetings, and the Company and Parent can mutually decide to terminate the Rio Tinto Transaction Agreement at any time prior to the closing. The Company expects to incur total transaction costs of approximately $129 million if the Rio Tinto Transaction closes, $23.2 million of which have been expensed and accrued in the Company's consolidated statement of operations and balance sheet for the year ended and as of December 31, 2024, respectively. The foregoing summary of the Rio Tinto Transaction Agreement and the Rio Tinto Transaction contemplated thereby does not purport to be complete and is qualified in its entirety by reference to the terms and conditions of the Rio Tinto Transaction Agreement, a copy of which is filed as Exhibit 2.5 to this Form 10-K.

Arcadium Lithium plc 10-K