EARNINGS PER SHARE AND REDEEMABLE NONCONTROLLING INTERESTS - Computation (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net income (loss) attributable to ATN International, Inc. stockholders- Basic	$ (32,691)	$ (3,584)	$ (30,000)	$ (8,702)
Less: Preferred dividends	(1,426)	(1,303)	(4,154)	(3,593)
Net income (loss) attributable to ATN International, Inc. common stockholders- Diluted	$ (34,117)	$ (4,887)	$ (34,154)	$ (12,295)
Denominator:
Weighted-average shares outstanding- Basic	15,114	15,601	15,268	15,666
Weighted-average shares outstanding- Diluted	15,114	15,601	15,268	15,666