ACQUISITIONS AND DISPOSITIONS - Unaudited pro forma operating results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
ACQUISITIONS AND DISPOSITIONS
Amount of pre-Close debt, and associated interest removed from pro forma results		$ 164,600		$ 164,600
Transaction debt included in pro forma results		283,000		283,000
Revenue	$ 182,213	166,760	$ 533,730	415,135
Net Income (loss) attributable to ATN International, Inc. Stockholders	$ (2,783)	$ (2,619)	$ (4,255)	$ 2,103
Earnings (loss) Per Share
Basic (in dollars per share)	$ (0.25)	$ (0.22)	$ (0.49)	$ 0.08
Diluted (in dollars per share)	$ (0.25)	$ (0.22)	$ (0.49)	$ 0.08
Pro Forma
Revenue		$ 180,214		$ 550,900
Net Income attributable to ATN International, Inc. Stockholders		4,778		5,089
Unaudited pro forma adjustments increased net income		$ 7,400		$ 3,000
Earnings Per Share
Basic (in dollars per share)		$ 0.22		$ 0.09
Diluted (in dollars per share)		$ 0.22		$ 0.09