Earnings (Loss) per Common Share (Basic Net Income (Loss) per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator:
Net income (loss) available to common stockholders	$ (55,129)	$ 1,099
Common Stock - Class A [Member]
Numerator:
Net income (loss) available to common stockholders	(50,072)	1,009
Less: Undistributed net income allocable to participating securities	0	(48)
Undistributed net income (loss) allocable to common stockholders	$ (50,072)	$ 961
Denominator:
Weighted average common shares outstanding	31,220	33,696
Basic net income (loss) attributable to GCI common stockholders per common share (USD per share)	$ (1.60)	$ 0.03
Common Stock - Class B [Member]
Numerator:
Net income (loss) available to common stockholders	$ (5,057)	$ 90
Less: Undistributed net income allocable to participating securities	0	0
Undistributed net income (loss) allocable to common stockholders	$ (5,057)	$ 90
Denominator:
Weighted average common shares outstanding	3,153	3,155
Basic net income (loss) attributable to GCI common stockholders per common share (USD per share)	$ (1.60)	$ 0.03