Nature of Operations and Basis of Presentation	9 Months Ended
Nature of Operations and Basis of Presentation	Dec. 31, 2024
Accounting Policies [Abstract]
Nature of Operations and Basis of Presentation	Nature of Operations and Basis of Presentation Anterix Inc (the “Company”) is the utility industry’s partner, empowering enhanced visibility, control and security for a modern grid. The Company’s vision is to deliver secure, scalable solutions enabled by private wireless broadband connectivity, for the benefit of utilities and the communities that they serve. As the largest holder of licensed spectrum in the 900 MHz band (896-901/935-940 MHz) throughout the contiguous United States, plus Hawaii, Alaska and Puerto Rico, the Company is uniquely positioned to deliver solutions that support secure, resilient and customer-controlled operations. The Company is focused on commercializing its spectrum assets and expanding the benefits and solutions it offers to enable the Company’s targeted utility and critical infrastructure customers to deploy private broadband networks. Business Developments Executive Chairman Retirement On December 30, 2024, the Company announced Morgan O’Brien’s retirement as a director, as Executive Chairman of the Board of Directors of the Company (the “Board”), and as an executive of the Company, each effective as of December 31, 2024. In addition, the Company entered into a consulting agreement with Mr. O’Brien. See Note 5 Related Party Transactions for further discussion. Furthermore, on December 30, 2024 the Company also announced that Thomas Kuhn, a current director and Vice Chair of the Board, was appointed as the Chairman of the Board, effective January 1, 2025. See Note 12 Subsequent Events for further discussion. Chief Executive Officer Transition On October 8, 2024, the Company announced the appointment of Scott Lang as President and Chief Executive Officer, to succeed Robert Schwartz effective by November 1, 2024 (the “CEO Transition”). As part of the CEO Transition, the Board also designated Mr. Lang as the Company’s principal executive officer for purposes of the rules and regulations of the U.S Securities and Exchange Commission (the “SEC”). Due to his service as an executive of the Company, effective as of the date of his appointment, Mr. Lang resigned from serving on the Board’s Audit Committee and Nominating and Governance Committee. In connection with Mr. Schwartz’s resignation, the Company negotiated a Transition and Separation Agreement (the “Transition Agreement”), which provided the following benefits (subject to effectiveness and the terms and conditions of the Transition Agreement), (i) two times the sum of his annualized salary and target bonus, for an aggregate amount of approximately $2.2 million, (ii) a pro-rata target bonus for fiscal year 2025, less amount previously paid for fiscal year 2025, for an aggregate amount of approximately $0.2 million and (iii) a subsidized COBRA continuation coverage for 18 months. Additionally, in connection with the Transition Agreement, unvested time-based awards and performance-based awards accelerated and vested on a pro-rated basis, and Mr. Schwartz received an option exercise period extension. See Note 8 Stockholders’ Equity for further discussion. Oncor Agreement In June 2024, the Company entered into a license purchase agreement with Oncor Electric Delivery Company LLC (“Oncor”) for total estimated consideration of $102.5 million under which Oncor will purchase 900 MHz spectrum licenses covering 95 counties to deploy a private wireless broadband network in its transmission and distribution service area (the “Oncor Agreement”). The total payment of $102.5 million comprises an initial payment of $10.0 million received in June 2024 with remaining payments due to the Company for each county, at closing. The timing and rights to milestone payments could vary as 900 MHz broadband licenses are granted by the Federal Communications Commission (the “FCC”), broadband licenses are assigned to Oncor and incumbents are cleared by the Company. Oncor operates more than 143,000 circuit miles of transmission and distribution lines in Texas, delivering electricity to more than four million homes and businesses across a service territory that has an estimated population of approximately 13 million people. See Note 10 Contingencies and Guaranty for further discussion on the Oncor Agreement. Basis of Presentation and Use of Estimates The consolidated financial statements and accompanying notes are prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information. Pursuant to the rules and regulations of the SEC, certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted, these unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes in the Company’s Annual Report on Form 10-K for the fiscal year ended March 31, 2024, filed with the SEC on June 26, 2024 (the “2024 Annual Report”). In the Company’s opinion, all normal and recurring adjustments considered necessary for a fair presentation of the financial position, results of operations and cash flows for the periods presented have been included. The Company believes that the disclosures made in the unaudited consolidated interim financial statements are adequate to make the information not misleading. The results of operations for the interim periods presented are not necessarily indicative of the results for the year. The Company is also required to make certain estimates and assumptions that affect the reported amounts. These estimates and assumptions are reviewed periodically, and the effects of revisions are reflected in the financial statements in the applicable period. Accordingly, actual results could materially differ from those estimates. The accompanying consolidated financial statements include the accounts of the Company and its subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Recently Issued Accounting Pronouncements In November 2024, the Financial Accounting Standards Board issued Accounting Standard Updates 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures. This update requires public business entities to disclose, on an annual and interim basis, disaggregated information about certain income statement expense line items in the notes to the financial statements. This update is effective for annual periods beginning after December 15, 2026, and interim periods within annual periods beginning after December 15, 2027. Early adoption is permitted and should be applied either prospectively or retroactively. The Company has not yet determined the impact of this pronouncement on its consolidated financial statements.