Note 2 - Revenue Recognition - Effect of Adoption of ASC 606 on the Company's Statement of Comprehensive Income and Balance Sheet (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Operating revenues	$ 58,689	$ 58,229	$ 59,578	$ 55,972	$ 54,935	$ 56,703	$ 58,536	$ 56,731	$ 232,468	$ 226,905
Total operating expenses									208,189	207,583
Operating income	4,885	5,763	8,288	5,343	5,166	3,672	5,756	4,728	24,279	19,322
Income before income tax expense									11,029	(3,646)
Net income (loss) attributable to Alaska Communications	$ 1,720	$ 1,817	$ 3,442	$ 2,101	$ (2,947)	$ 320	$ (2,798)	$ (676)	$ 9,080	$ (6,101)
Basic (in dollars per share)	$ 0.03	$ 0.03	$ 0.06	$ 0.04	$ (0.06)	$ 0.01	$ (0.05)	$ (0.01)	$ 0.17	$ (0.12)
Diluted (in dollars per share)	$ 0.03	$ 0.03	$ 0.06	$ 0.04	$ (0.06)	$ 0.01	$ (0.05)	$ (0.01)	$ 0.17	$ (0.12)
Deferred income taxes	$ 498				$ 3,394				$ 498	$ 3,394
Other assets	16,010				11,415				16,010	11,415
Total assets	455,185				442,786				455,185	442,786
Deferred income taxes	2,315				596				2,315	596
Total liabilities	285,435				288,276				285,435	288,276
Retained earnings	10,439				$ (3,579)				10,439	$ (3,579)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Operating revenues
Total operating expenses									1,154
Operating income									(1,154)
Income before income tax expense									(1,154)
Net income (loss) attributable to Alaska Communications									$ (826)
Basic (in dollars per share)									$ (0.01)
Diluted (in dollars per share)									$ (0.02)
Deferred income taxes	1,533								$ 1,533
Other assets	(8,052)								(8,052)
Total assets	(6,519)								(6,519)
Deferred income taxes	(755)								(755)
Total liabilities	(755)								(755)
Retained earnings	(5,764)								(5,764)
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Operating revenues									232,468
Total operating expenses									209,343
Operating income									23,125
Income before income tax expense									9,875
Net income (loss) attributable to Alaska Communications									$ 8,254
Basic (in dollars per share)									$ 0.16
Diluted (in dollars per share)									$ 0.15
Deferred income taxes	2,031								$ 2,031
Other assets	7,958								7,958
Total assets	448,666								448,666
Deferred income taxes	1,560								1,560
Total liabilities	284,680								284,680
Retained earnings	$ 4,675								$ 4,675