| **Earnings (Loss) Per Common Share (Diluted Net Income (Loss) Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands** | 3 Months Ended | 6 Months Ended |
|---------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|----------------|
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| Common Stock - Class A [Member]                                                                                                                         |           |           |   |   |
| **Numerator [Abstract]**                                                                                                                                |           |           |   |   |
| Undistributed income (loss) allocable to common stockholders for basic computation                                                                      | $ 2,967        | $ (14,330)     | $ 3,934 | $ (32,048) |
| Reallocation of undistributed earnings (loss) as a result of conversion of Class B to Class A shares                                                    | 281            | (1,297)        | 370 | (2,848) |
| Reallocation of undistributed earnings as a result of conversion of dilutive securities                                                                 | 189            | 0              | 304 | 0 |
| Effect of derivative instruments that may be settled in cash or shares                                                                                  | (3,834)        | 0              | (6,501) | 0 |
| Effect of share based compensation that may be settled in cash or shares                                                                                | (39)           | 0              | (62) | 0 |
| Undistributed net income (loss) adjusted for allocation of undistributed earnings (loss) and effect of contracts that may be settled in cash or shares  | $ (436)        | $ (15,627)     | $ (1,955) | $ (34,896) |
| **Denominator [Abstract]**                                                                                                                              |           |           |   |   |
| Number of shares used in basic computation                                                                                                              | 33,308         | 34,887         | 33,502 | 35,548 |
| Conversion of Class B to Class A common shares outstanding                                                                                              | 3,155          | 3,159          | 3,155 | 3,159 |
| Effect of derivative instruments that may be settled in cash or shares                                                                                  | 611            | 0              | 744 | 0 |
| Effect of share based compensation that may be settled in cash or shares                                                                                | 26             | 0              | 26 | 0 |
| Number of shares used in per share computation                                                                                                          | 37,100         | 38,046         | 37,427 | 38,707 |
| Diluted net loss attributable to GCI common stockholders per common share                                                                               | $ (0.01)       | $ (0.41)       | $ (0.05) | $ (0.90) |
| Common Stock - Class B [Member]                                                                                                                         |           |           |   |   |
| **Numerator [Abstract]**                                                                                                                                |           |           |   |   |
| Undistributed income (loss) allocable to common stockholders for basic computation                                                                      | $ 281          | $ (1,297)      | $ 370 | $ (2,848) |
| Reallocation of undistributed earnings (loss) as a result of conversion of Class B to Class A shares                                                    | 0              | 0              | 0 | 0 |
| Reallocation of undistributed earnings as a result of conversion of dilutive securities                                                                 | (319)          | 0              | (536) | 0 |
| Effect of derivative instruments that may be settled in cash or shares                                                                                  | 0              | 0              | 0 | 0 |
| Effect of share based compensation that may be settled in cash or shares                                                                                | 0              | 0              | 0 | 0 |
| Undistributed net income (loss) adjusted for allocation of undistributed earnings (loss) and effect of contracts that may be settled in cash or shares  | $ (38)         | $ (1,297)      | $ (166) | $ (2,848) |
| **Denominator [Abstract]**                                                                                                                              |           |           |   |   |
| Number of shares used in basic computation                                                                                                              | 3,155          | 3,159          | 3,155 | 3,159 |
| Conversion of Class B to Class A common shares outstanding                                                                                              | 0              | 0              | 0 | 0 |
| Effect of derivative instruments that may be settled in cash or shares                                                                                  | 0              | 0              | 0 | 0 |
| Effect of share based compensation that may be settled in cash or shares                                                                                | 0              | 0              | 0 | 0 |
| Number of shares used in per share computation                                                                                                          | 3,155          | 3,159          | 3,155 | 3,159 |
| Diluted net loss attributable to GCI common stockholders per common share                                                                               | $ (0.01)       | $ (0.41)       | $ (0.05) | $ (0.90) |

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Dilutive Securities, Effect on Basic Earnings Per Share, Derivative Instruments Convertible Into Shares or Cash
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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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Reallocation of undistributed earnings in the calculation of diluted EPS as a result of the potentially dilutive effect of conversion of Class B common shares to Class A common shares using if-converted method.
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Undistributed Income (Loss) Available to Common Stockholders
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| - Definition
Amount of increase (decrease) to net income used for calculating diluted earnings per share (EPS), resulting from the assumed exercise of dilutive convertible securities excluding adjustments related to ESOP convertible preferred stock, stock options, and restrictive stock units.
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
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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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
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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| - Definition
The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.
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| - Definition
Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.
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