CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total ATNI Stockholders' Equity Cumulative Effect, Period of Adoption, Adjustment	Total ATNI Stockholders' Equity	Common Stock	Treasury Stock, at cost	Additional Paid In Capital	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings	Accumulated Other Comprehensive Income/(Loss) Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income/(Loss)	Non-Controlling Interests Cumulative Effect, Period of Adoption, Adjustment	Non-Controlling Interests	Cumulative Effect, Period of Adoption, Adjustment	Total
Balance, beginning of period at Dec. 31, 2017	$ 1,490	$ 688,727	$ 170	$ (36,110)	$ 167,973	$ 1,693	$ 552,948	$ (203)	$ 3,746	$ 1,146	$ 141,496	$ 2,636	$ 830,223
Increase (Decrease) in Stockholders' Equity
Issuance of restricted shares of common stock		2	2										2
Issuance of shares of common stock upon exercise of stock options		6,319			6,319								6,319
Purchase of shares of common stock		(12,437)		(12,437)									(12,437)
Stock-based compensation		6,420			6,420								6,420
Dividends declared on common stock		(10,863)					(10,863)						(10,863)
Distributions to non-controlling interests											(19,033)		(19,033)
Repurchase of non-controlling interests		1,066			1,066						(10,729)		(9,663)
Comprehensive income:
Net income (loss)		19,815					19,815				15,057		34,872
Other comprehensive income (loss)		(5,152)							(5,152)				(5,152)
Comprehensive income		14,663									15,057		29,720
Balance, end of period at Dec. 31, 2018		695,387	172	(48,547)	181,778		563,593		(1,609)		127,937		823,324
Increase (Decrease) in Stockholders' Equity
Issuance of shares of common stock upon exercise of stock options		771			771								771
Purchase of shares of common stock		(2,582)		(2,582)									(2,582)
Stock-based compensation		5,922			5,922						462		6,384
Dividends declared on common stock		(10,897)					(10,897)						(10,897)
Distributions to non-controlling interests											(7,195)		(7,195)
Repurchase of non-controlling interests											(4,504)		(4,504)
Investments made by minority shareholders in consolidated affiliates											488		488
Comprehensive income:
Net income (loss)		(10,806)					(10,806)				12,773		1,967
Other comprehensive income (loss)		(1,673)							(1,673)				(1,673)
Comprehensive income		(12,479)									12,773		294
Balance, end of period at Dec. 31, 2019		676,122	172	(51,129)	188,471		541,890		(3,282)		129,961		806,083
Increase (Decrease) in Stockholders' Equity
Purchase of shares of common stock		(8,327)		(8,327)									(8,327)
Stock-based compensation		5,603			5,603						309		5,912
Dividends declared on common stock		(10,867)					(10,867)						(10,867)
Distributions to non-controlling interests											(12,378)		(12,378)
Repurchase of non-controlling interests		(5,020)			(5,020)						(23,919)		(28,939)
Investments made by minority shareholders in consolidated affiliates		(1,300)			(1,300)						1,300
Comprehensive income:
Net income (loss)		(14,122)					(14,122)				13,414		(708)
Other comprehensive income (loss)		3,560							3,560				3,560
Comprehensive income		(10,562)									13,414		2,852
Balance, end of period at Dec. 31, 2020		$ 645,649	$ 172	$ (59,456)	$ 187,754		$ 516,901		$ 278		$ 108,687		$ 754,336