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		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator:
Net income (loss) attributable to ATN International, Inc. stockholders	$ (525)	$ 2,019	$ (1,471)	$ 4,723
Less: Preferred dividends	(1,154)		(2,270)
Net income (loss) attributable to ATN International, Inc. common stockholders	$ (1,679)	$ 2,019	$ (3,741)	$ 4,723
Denominator:
Weighted-average shares outstanding- Basic	15,749	15,912	15,736	15,907
Stock options, restricted stock units and performance stock units		9		23
Weighted-average shares outstanding- Diluted	15,749	15,921	15,736	15,930