Earnings (Loss) per Common Share (Diluted Net Income (Loss) Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Common Stock - Class A [Member]
Numerator:
Undistributed net income (loss) allocable to common stockholders for basic computation	$ (50,072)	$ 961
Reallocation of undistributed earnings as a result of conversion of Class B to Class A shares	(5,057)	90
Reallocation of undistributed earnings as a result of conversion of dilutive securities	0	117
Effect of derivative instrument that may be settled in cash or shares	0	(2,668)
Effect of share based compensation that may be settled in cash or shares	0	(23)
Undistributed net loss adjusted for allocation of undistributed earnings (loss) and effect of contracts that may be settled in cash or shares	$ (55,129)	$ (1,523)
Denominator:
Number of shares used in basic computation	31,220	33,696
Conversion of Class B to Class A common shares outstanding	3,153	3,155
Effect of derivative instrument that may be settled in cash or shares	0	869
Effect of share based compensation that may be settled in cash or shares	0	26
Number of shares used in per share computation	34,373	37,746
Diluted net loss attributable to GCI common stockholders per common share (USD per share)	$ (1.60)	$ (0.04)
Common Stock - Class B [Member]
Numerator:
Undistributed net income (loss) allocable to common stockholders for basic computation	$ (5,057)	$ 90
Reallocation of undistributed earnings as a result of conversion of Class B to Class A shares	0	0
Reallocation of undistributed earnings as a result of conversion of dilutive securities	0	(217)
Effect of derivative instrument that may be settled in cash or shares	0	0
Effect of share based compensation that may be settled in cash or shares	0	0
Undistributed net loss adjusted for allocation of undistributed earnings (loss) and effect of contracts that may be settled in cash or shares	$ (5,057)	$ (127)
Denominator:
Number of shares used in basic computation	3,153	3,155
Conversion of Class B to Class A common shares outstanding	0	0
Effect of derivative instrument that may be settled in cash or shares	0	0
Effect of share based compensation that may be settled in cash or shares	0	0
Number of shares used in per share computation	3,153	3,155
Diluted net loss attributable to GCI common stockholders per common share (USD per share)	$ (1.60)	$ (0.04)