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GOVERNMENT SUPPORT AND SPECTRUM MATTERS - Narrative (Details) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Dec. 31, 2024 | Sep. 30, 2025 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024 | Jul. 31, 2022
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Government capital programs - Amounts received |  |  | $ 61,145 | $ 72,531 |  |
Grant funds awarded during the period |  |  | 16,097 |  |  |
Amounts accrued for reimbursable capital expenditures from government capital programs |  |  | 13,634 | $ 32,467 |  |
Alaska Connect Fund | Grant receivable from January 1, 2025 through December 2028 |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Grants expected to be received per year |  | $ 25,600 | 25,600 |  |  |
Universal Service Fund programs |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Grant funds awarded annually |  |  | 2,500 |  |  |
Connect America Fund II |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Grant funds awarded annually |  |  | 8,000 |  |  |
Connect America Fund Phase II Program in Alaska |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Grant funds awarded annually |  |  |  |  | $ 19,700 |
Enhanced Alternative Connect America Cost Model |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Amount that has been funded or will be funded |  | 102,600 | $ 102,600 |  |  |
Grant fund term |  |  | 14 years |  |  |
Enhanced Alternative Connect America Cost Model | Grant receivable through 2030 |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Amount that has been funded or will be funded |  | 9,000 | $ 9,000 |  |  |
Enhanced Alternative Connect America Cost Model | Grant receivable in year 2038 |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Amount that has been funded or will be funded |  | 6,000 | 6,000 |  |  |
High cost support program | Communication services | International Telecom |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Government capital programs - Amounts received |  |  | $ 5,500 |  |  |
Rural Digital Opportunity Fund Phase I |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Grant fund term |  |  | 10 years |  |  |
Term to deploy voice and broadband service to covered areas |  |  | 6 years |  |  |
Grant funds awarded annually |  |  | $ 2,300 |  |  |
Transfer of annual awards |  |  | 1,300 |  |  |
Return of grants to FCC |  |  | 700 |  |  |
Loss on disposition of assets and transfers |  | 1,900 |  |  |  |
Accounts payable and accrued liabilities |  | $ 2,700 | 2,700 |  |  |
TBCP and Reconnect |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Government capital programs - Amounts received |  |  | 34,000 |  |  |
Grant funds awarded during the period |  |  | 239,000 |  |  |
Spent construction obligations |  |  | 31,900 |  |  |
Replace and Remove Program |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Cost reimbursement amount funded | $ 517,000 |  |  |  |  |
Amounts accrued for reimbursable capital expenditures from government capital programs |  |  | $ 11,000 |  |  |
Reimbursement period |  |  | 12 months |  |  |
Replace and Remove Program | Maximum |  |  |  |  |  |
GOVERNMENT SUPPORT AND SPECTRUM MATTERS |  |  |  |  |  |
Amount of cost reimbursement allocated |  |  |  |  |  | $ 207,000

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