Business and Summary of Significant Accounting Principles (Diluted EPS calculations) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Common Stock - Class A [Member]
Class of Stock [Line Items]
Allocation of undistributed earnings (loss) for basic computation	$ (17,723)	$ 999
Reallocation of undistributed earnings (loss) as a result of conversion of Class B to Class A shares	(1,546)	88
Net income (loss) adjusted for allocation of undistributed earnings and effect of contracts that may be settled in cash or shares	(19,269)	1,087
Number of shares used in basic computation	36,217	36,081
Conversion of Class B to Class A common shares outstanding	3,159	3,163
Unexercised stock options	0	118
Number of shares used in per share computation	39,376	39,362
Diluted net income (loss) attributable to GCI common stockholders per common share	$ (0.49)	$ 0.03
Common Stock - Class B [Member]
Class of Stock [Line Items]
Allocation of undistributed earnings (loss) for basic computation	(1,546)	88
Reallocation of undistributed earnings (loss) as a result of conversion of Class B to Class A shares	0	0
Net income (loss) adjusted for allocation of undistributed earnings and effect of contracts that may be settled in cash or shares	$ (1,546)	$ 88
Number of shares used in basic computation	3,159	3,163
Conversion of Class B to Class A common shares outstanding	0	0
Unexercised stock options	0	0
Number of shares used in per share computation	3,159	3,163
Diluted net income (loss) attributable to GCI common stockholders per common share	$ (0.49)	$ 0.03

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible class B stock using if-converted method.

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Undistributed Income (Loss) Available to Common Stockholders

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Net Income or Loss Available to Common Stockholders plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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