REVENUE AND RECEIVABLES - Remaining Performance Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Revenue Recognition
Transaction price allocated to unsatisfied performance obligations		$ 494
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue Recognition
Transaction price allocated to unsatisfied performance obligations	$ 598
Percentage of performance obligations to be satisfied	43.00%
Period to satisfy the remaining performance obligations and recognize the transaction price	24 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue Recognition
Transaction price allocated to unsatisfied performance obligations	$ 60
Period to satisfy the remaining performance obligations and recognize the transaction price	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue Recognition
Transaction price allocated to unsatisfied performance obligations	$ 60
Period to satisfy the remaining performance obligations and recognize the transaction price	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
Revenue Recognition
Transaction price allocated to unsatisfied performance obligations	$ 60
Period to satisfy the remaining performance obligations and recognize the transaction price	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01
Revenue Recognition
Transaction price allocated to unsatisfied performance obligations	$ 60
Period to satisfy the remaining performance obligations and recognize the transaction price	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2030-01-01
Revenue Recognition
Transaction price allocated to unsatisfied performance obligations	$ 60
Period to satisfy the remaining performance obligations and recognize the transaction price	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2031-01-01
Revenue Recognition
Transaction price allocated to unsatisfied performance obligations	$ 60
Period to satisfy the remaining performance obligations and recognize the transaction price	12 months

ATN International, Inc. 10-K