GOVERNMENT SUPPORT AND SPECTRUM MATTERS - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Dec. 31, 2024	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Jul. 31, 2022
Mobility Fund [Line Items]
Government capital programs - Amounts received		$ 17,281	$ 10,546
Amounts accrued for reimbursable capital expenditures from government capital programs		22,191	$ 33,446
Alaska Connect Fund | Grant receivable from January 1, 2025 through December 2028
Mobility Fund [Line Items]
Grants expected to be received per year		25,600
Universal Service Fund programs
Mobility Fund [Line Items]
Grant funds awarded annually		2,500
Connect America Fund II
Mobility Fund [Line Items]
Grant funds awarded annually		8,000			$ 19,700
Enhanced Alternative Connect America Cost Model
Mobility Fund [Line Items]
Amount that has been funded or will be funded		$ 109,000
Grant fund term		14 years
Enhanced Alternative Connect America Cost Model | Grant receivable through 2030
Mobility Fund [Line Items]
Amount that has been funded or will be funded		$ 9,000
Enhanced Alternative Connect America Cost Model | Grant receivable in year 2038
Mobility Fund [Line Items]
Amount that has been funded or will be funded		6,000
High cost support program | Communication services | International Telecom
Mobility Fund [Line Items]
Government capital programs - Amounts received		$ 5,500
Rural Digital Opportunity Fund Phase I
Mobility Fund [Line Items]
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				$ 300
Accounts payable and accrued liabilities		4,900
TBCP and Reconnect
Mobility Fund [Line Items]
Government capital programs - Amounts received		23,200
Grant funds awarded during the period		237,000
Spent construction obligations		22,200
Replace and Remove Program
Mobility Fund [Line Items]
Cost reimbursement amount funded	$ 517,000
Amounts accrued for reimbursable capital expenditures from government capital programs		$ 19,500
Reimbursement period		12 months
Replace and Remove Program | Maximum
Mobility Fund [Line Items]
Amount of cost reimbursement allocated						$ 207,000