CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total ATNI Stockholders' Equity	Common Stock	Treasury Stock, at cost	Additional Paid In Capital	Retained Earnings	Accumulated Other Comprehensive Income/(Loss)	Non-Controlling Interests	Total
Increase (Decrease) in Stockholders' Equity
Cumulative effect adjustment due to adoption of new accounting	$ 155			$ 341	$ (186)			$ 155
Balance, beginning of period at Dec. 31, 2016	677,055	$ 169	$ (23,127)	160,176	538,109	$ 1,728	$ 132,114	809,169
Increase (Decrease) in Stockholders' Equity
Issuance of restricted shares of common stock	1	1						1
Issuance of shares of common stock upon exercise of stock options	1,156			1,156				1,156
Purchase of shares of common stock	(12,983)		(12,983)					(12,983)
Stock-based compensation	6,970			6,970				6,970
Dividends declared on common stock	(16,465)				(16,465)		(7,318)	(23,783)
Repurchase of non-controlling interests	(670)			(670)			(1,356)	(2,026)
Investments made by minority shareholders in consolidated affiliates							123	123
Deconsolidation of a subsidiary							529	529
Comprehensive income:
Net income (loss)	31,490				31,490		17,404	48,894
Other comprehensive income (loss)	2,018					2,018		2,018
Comprehensive income	33,508						17,404	50,912
Balance, end of period at Dec. 31, 2017	688,727	170	(36,110)	167,973	552,948	3,746	141,496	830,223
Increase (Decrease) in Stockholders' Equity
Cumulative effect adjustment due to adoption of new accounting	1,490				1,693	(203)	1,146	2,636
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)		(19,033)	(29,896)
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)		(7,195)	(18,092)
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