Earnings (Loss) per Common Share (Basic Net Income (Loss) per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator:
Net income (loss) available to common stockholders	$ (8,882)	$ 3,415	$ (64,011)	$ 4,514
Common Stock - Class A [Member]
Numerator:
Net income (loss) available to common stockholders	(8,086)	3,134	(58,207)	4,144
Less: Undistributed net income allocable to participating securities	0	(167)	0	(210)
Undistributed net income (loss) allocable to common stockholders	$ (8,086)	$ 2,967	$ (58,207)	$ 3,934
Denominator:
Weighted average common shares outstanding	31,276	33,308	31,248	33,502
Basic net income (loss) attributable to GCI common stockholders per common share (USD per share)	$ (0.26)	$ 0.09	$ (1.86)	$ 0.12
Common Stock - Class B [Member]
Numerator:
Net income (loss) available to common stockholders	$ (796)	$ 281	$ (5,804)	$ 370
Less: Undistributed net income allocable to participating securities	0	0	0	0
Undistributed net income (loss) allocable to common stockholders	$ (796)	$ 281	$ (5,804)	$ 370
Denominator:
Weighted average common shares outstanding	3,078	3,155	3,116	3,155
Basic net income (loss) attributable to GCI common stockholders per common share (USD per share)	$ (0.26)	$ 0.09	$ (1.86)	$ 0.12