Nature of Operations and Basis of Presentation	3 Months Ended
Nature of Operations and Basis of Presentation	Jun. 30, 2025
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. 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, 2025, filed with the SEC on June 24, 2025 (the “2025 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 December 2023, the Financial Accounting Standards Board, (“FASB”) issued Accounting Standards Updates (“ASU”) 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which enhances transparency about income tax information through improvements to income tax disclosures primarily related to the rate reconciliation and income taxes paid and to improve the effectiveness of income tax disclosures. This update is effective for annual periods beginning after December 15, 2024. The Company has not yet determined the impact of this pronouncement on its consolidated financial statements and related disclosures. In November 2024, the FASB issued ASU 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures and subsequently amended with ASU 2025-01, which was issued in January 2025. 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.