CONSOLIDATED STATEMENTS OF STOCKHOLDER'S EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock Class A	Shares of Class A Common Stock Common Stock Class A	Paid-in Capital	Retained Deficit	Non- controlling Interests
Beginning balances, common stock, shares at Dec. 31, 2015			100
Beginning balances, total stockholders' equity at Dec. 31, 2015	$ 210,095		$ 206,622	$ 164,508	$ (192,033)	$ 30,998
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(1,069)				(719)	(350)
Distribution to General Communication, Inc.	(53,280)				(53,280)
Contribution from General Communication, Inc.	8,174			8,174
Ending balances, common stock, shares at Sep. 30, 2016			100
Ending balances, total stockholders' equity at Sep. 30, 2016	163,920		$ 206,622	172,682	(246,032)	30,648
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of ASU 2016-09 adoption	7,095			18	7,077
Beginning balances, common stock, shares at Dec. 31, 2016		100	100
Beginning balances, total stockholders' equity at Dec. 31, 2016	140,917		$ 206,622	161,310	(257,544)	30,529
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(21,294)				(20,941)	(353)
Distribution to General Communication, Inc.	(11,537)				(11,537)
Contribution from General Communication, Inc.	13,264			13,264
Investment by non-controlling interest	2,709					2,709
Ending balances, common stock, shares at Sep. 30, 2017		100	100
Ending balances, total stockholders' equity at Sep. 30, 2017	$ 131,154		$ 206,622	$ 174,592	$ (282,945)	$ 32,885