{"cik":2071778,"taxonomy":"us-gaap","tag":"DebtInstrumentCarryingAmount","label":"Long-term Debt, Gross","description":"Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.","entityName":"Fermi Inc.","units":{"USD":[{"end":"2025-12-31","val":148986000,"accn":"0002071778-26-000032","fy":2026,"fp":"Q1","form":"10-Q","filed":"2026-05-15"},{"end":"2025-12-31","val":148986000,"accn":"0002071778-26-000051","fy":2026,"fp":"Q2","form":"10-Q","filed":"2026-08-14","frame":"CY2025Q4I"},{"end":"2026-03-31","val":439127000,"accn":"0002071778-26-000032","fy":2026,"fp":"Q1","form":"10-Q","filed":"2026-05-15","frame":"CY2026Q1I"},{"end":"2026-06-30","val":536904000,"accn":"0002071778-26-000051","fy":2026,"fp":"Q2","form":"10-Q","filed":"2026-08-14","frame":"CY2026Q2I"}]}}