CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Non-related party	$ 919,204,000	$ 933,812,000	$ 973,251,000
Related party	0	0	5,283,000
Total revenues	919,204,000	933,812,000	978,534,000
Cost of goods sold (exclusive of depreciation and amortization shown separately below):
Non-related party	280,200,000	302,578,000	321,457,000
Related party	0	0	881,000
Total cost of goods sold	280,200,000	302,578,000	322,338,000
Selling, general and administrative expenses
Non-related party	370,639,000	358,356,000	337,839,000
Related party	0	0	540,000
Total selling, general and administrative expenses	370,639,000	358,356,000	338,379,000
Depreciation and amortization expense	197,115,000	193,775,000	181,767,000
Software impairment charge	0	0	29,839,000
Operating income	71,250,000	79,103,000	106,211,000
Other income (expense):
Interest expense (including amortization of deferred loan fees)	(83,341,000)	(78,628,000)	(78,786,000)
Loss on extinguishment of debt	(649,000)	(640,000)	(27,700,000)
Impairment of equity method investment	0	0	(12,593,000)
Other	2,938,000	5,569,000	2,917,000
Other expense, net	(81,052,000)	(73,699,000)	(116,162,000)
Income (loss) before income taxes	(9,802,000)	5,404,000	(9,951,000)
Income tax (expense) benefit	41,117,000	(7,080,000)	(81,000)
Net income (loss)	31,315,000	(1,676,000)	(10,032,000)
Net income (loss) attributable to non-controlling interests	(476,000)	(469,000)	159,000
Net income (loss) attributable to GCI, Inc.	$ 31,791,000	$ (1,207,000)	$ (10,191,000)