ACQUISITIONS AND DISPOSITIONS - Unaudited pro forma operating results (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
ACQUISITIONS AND DISPOSITIONS
Amount of pre-Close debt, and associated interest removed from pro forma results			$ 164,600
Transaction debt included in pro forma results			283,000
Revenue	$ 762,216	$ 725,745	602,707
Net loss attributable to ATN International, Inc. Stockholders	$ (14,538)	$ (5,645)	$ (22,108)
Net income (loss) per weighted average basic share attributable to ATN International, Inc. stockholders
Basic (in dollars per share)	$ (1.25)	$ (0.67)	$ (1.52)
Diluted (in dollars per share)	$ (1.25)	$ (0.67)	$ (1.52)
Pro Forma
Revenue			$ 738,472
Net loss attributable to ATN International, Inc. Stockholders			$ (20,022)
Earnings Per Share
Basic (in dollars per share)			$ (1.26)
Diluted (in dollars per share)			$ (1.26)
Unaudited pro forma adjustments increased net loss			$ 2,100