Revenue Recognition - Impacts of adoption in the current period - IS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Revenue	$ 104,475	$ 128,115
Sales, marketing and customer service	8,562	9,035
Total expenses	100,266	110,359
Income from operations	4,209	17,756
Income before taxes	1,618	14,712
Income tax provisions	3,921	3,128
Net income (loss)	(2,303)	11,584
Net income attributable to non-controlling interests	(3,252)	(4,725)
Net loss attributable to ATN International, Inc. stockholders	(5,555)	6,859
ASU 2014-09 | Change
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Revenue	133
Sales, marketing and customer service	(378)
Total expenses	(378)
Income from operations	511
Income before taxes	511
Income tax provisions	93
Net income (loss)	418
Net income attributable to non-controlling interests	(181)
Net loss attributable to ATN International, Inc. stockholders	237
ASU 2014-09 | Under previous guidance
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Revenue	104,342
Sales, marketing and customer service	8,940
Total expenses	100,644
Income from operations	3,698
Income before taxes	1,107
Income tax provisions	3,828
Net income (loss)	(2,721)
Net income attributable to non-controlling interests	(3,071)
Net loss attributable to ATN International, Inc. stockholders	(5,792)
Wireless
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Revenue	50,548	$ 58,925
Wireless | ASU 2014-09 | Change
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Revenue	133
Wireless | ASU 2014-09 | Under previous guidance
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Revenue	$ 50,415