ACQUISITIONS - Purchase Price Allocation (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended		6 Months Ended
	Jul. 01, 2016	May 03, 2016	Apr. 07, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Consideration Transferred
Total consideration		$ 41,563
Total value to allocate
Value to allocate		74,472
Preliminary purchase price allocation:
Goodwill				$ 40,865		$ 40,865		$ 45,077
Gain on KeyTech bargain purchase				(7,304)		(7,304)
Purchase price allocation BDC:
Revenue				99,991	$ 90,326	189,676	$ 175,670
Rural Telephone Finance Cooperative )RTFC)
Consideration Transferred
Debt instrument, face amount	$ 60,000
CellOne [Member]
Purchase price allocation BDC:
Carrying value of BDC non-controlling interest acquiredCarrying value of BDC non-controlling interest acquired		2,940
Excess of purchase price paid over carrying value of non-controlling interest acquired		4,105
Bermuda wireless operations
Consideration Transferred
Total consideration		7,045
Total value to allocate
Value to allocate		7,045
Vibrant Energy Investment [Member]
Consideration Transferred
Total consideration			$ 6,193
Preliminary purchase price allocation:
Cash			136
Prepayments and other assets			636
Plant and equipment			7,321
Accounts payable and accrued liabilities			(5,179)
Goodwill			3,279
Net assets acquired			$ 6,193
Purchase price allocation BDC:
Revenue						100
KeyTech [Member]
Consideration Transferred
Total consideration		34,518
Non-controlling interests		32,909
Total value to allocate
Value to allocate		67,427
Preliminary purchase price allocation:
Cash		8,185
Accounts receivable		6,451
Other current assets		3,241
Plant and equipment		100,892
Identifiable intangible assets		10,590
Other long term assets		3,464
Accounts payable and accrued liabilities		(16,051)
Advance payments and deposits		(6,683)
Current debt		(6,429)
Long-term debt		(28,929)
Net assets acquired		74,731
Gain on KeyTech bargain purchase		7,304
Non-controlling interests		32,909
Purchase price allocation BDC:
Revenue						14,000
External acquisition related charges relating to legal, accounting and consulting services.		$ 4,100		3,200		3,200
Pro Forma (unaudited)
Revenue				107,006	112,181	231,757	218,510
Net income attributable to ATN stockholders				$ (1,157)	$ 9,746	$ 9,935	$ 25,673
Earnings per shares:
Basic (in dollars per share)				$ (0.07)	$ 0.61	$ 0.62	$ 1.61
Diluted (in dollars per share)				$ (0.07)	$ 0.60	$ 0.61	$ 1.59
Innovative [Member]
Consideration Transferred
Total consideration	145,000
Cash-on-hand used to fund the purchase price	$ 85,000
As reported | KeyTech [Member]
Pro Forma (unaudited)
Revenue				$ 99,991	$ 90,326	$ 189,676	$ 175,670
Net income attributable to ATN stockholders				$ (3,086)	$ 9,450	$ 3,034	$ 6,181
Earnings per shares:
Basic (in dollars per share)				$ (0.19)	$ 0.59	$ 0.19	$ 0.38
Diluted (in dollars per share)				$ (0.19)	$ 0.59	$ 0.19	$ 0.38