EARNINGS PER SHARE AND REDEEMABLE NONCONTROLLING INTERESTS - Computation of basic and diluted earnings per share (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net loss attributable to ATN International, Inc. stockholders	$ (948)	$ 2,706
Less: Preferred dividends	(1,116)
Net loss attributable to ATN International, Inc. common stockholders	$ (2,064)	$ 2,706
Denominator:
Weighted-average shares outstanding- Basic	15,708	15,902
Stock options, restricted stock units and performance stock units		50
Weighted-average shares outstanding- Diluted	15,708	15,952