| **Earnings (Loss) per Common Share Earnings (Loss) per Common Share (Diluted) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands** | 3 Months Ended | 12 Months Ended |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|-----------------|
||
| Class A Common Stock                                                                                                                                         |           |            |   |   |   |   |   |   |   |   |   |
| **Numerator [Abstract]**                                                                                                                                     |           |            |   |   |   |   |   |   |   |   |   |
| Undistributed Income (Loss) Available to Common Stockholders                                                                                                 |           |            |   |   |   |   |   |   | $ (3,343) | $ (23,858) | $ 6,595 |
| Undistributed Earnings (Loss) Allocated to Participating Securities, Basic                                                                                   |           |            |   |   |   |   |   |   | (324) | (2,167) | 577 |
| Reallocation of undistributed loss as a result of conversion of dilutive securities                                                                          |           |            |   |   |   |   |   |   | 0 | 0 | 1 |
| Effect of derivative instrument that may be settled in cash or shares                                                                                        |           |            |   |   |   |   |   |   | (1,837) |   |   |
| Effect of share based compensation that may be settled in cash or shares                                                                                     |           |            |   |   |   |   |   |   | (5) |   |   |
| Net income (loss) adjusted for allocation of undistributed earnings and effect of contracts that may be settled in cash or shares                            |           |            |   |   |   |   |   |   | $ (5,509) | $ (26,025) | $ 7,173 |
| **Denominator [Abstract]**                                                                                                                                   |           |            |   |   |   |   |   |   |   |   |   |
| Weighted average common shares outstanding                                                                                                                   |           |            |   |   |   |   |   |   | 32,526 | 34,764 | 36,112 |
| Conversion of Class B to Class A common shares outstanding                                                                                                   |           |            |   |   |   |   |   |   | 3,154 | 3,157 | 3,162 |
| Effect of derivative instrument that may settled in cash or shares                                                                                           |           |            |   |   |   |   |   |   | 612 |   |   |
| Effect of share based compensation that may be settled in cash or shares                                                                                     |           |            |   |   |   |   |   |   | 26 |   |   |
| Unexercised stock options                                                                                                                                    |           |            |   |   |   |   |   |   |   | 0 | 112 |
| Number of shares used in per share computation                                                                                                               |           |            |   |   |   |   |   |   | 36,318 | 37,921 | 39,386 |
| Diluted net income (loss) attributable to General Communication, Inc. common stockholders per common share (USD per share)                                   | $ (0.47)       | $ 0.14          | $ (0.01) | $ (0.04) | $ (0.24) | $ 0.44 | $ (0.41) | $ (0.49) | $ (0.15) | $ (0.69) | $ 0.18 |
| Class B Common Stock                                                                                                                                         |           |            |   |   |   |   |   |   |   |   |   |
| **Numerator [Abstract]**                                                                                                                                     |           |            |   |   |   |   |   |   |   |   |   |
| Undistributed Income (Loss) Available to Common Stockholders                                                                                                 |           |            |   |   |   |   |   |   | $ (324) | $ (2,167) | $ 577 |
| Undistributed Earnings (Loss) Allocated to Participating Securities, Basic                                                                                   |           |            |   |   |   |   |   |   | 0 | 0 | 0 |
| Reallocation of undistributed loss as a result of conversion of dilutive securities                                                                          |           |            |   |   |   |   |   |   | (154) | 0 | (2) |
| Effect of derivative instrument that may be settled in cash or shares                                                                                        |           |            |   |   |   |   |   |   | 0 |   |   |
| Effect of share based compensation that may be settled in cash or shares                                                                                     |           |            |   |   |   |   |   |   | 0 |   |   |
| Net income (loss) adjusted for allocation of undistributed earnings and effect of contracts that may be settled in cash or shares                            |           |            |   |   |   |   |   |   | $ (478) | $ (2,167) | $ 575 |
| **Denominator [Abstract]**                                                                                                                                   |           |            |   |   |   |   |   |   |   |   |   |
| Weighted average common shares outstanding                                                                                                                   |           |            |   |   |   |   |   |   | 3,154 | 3,157 | 3,162 |
| Conversion of Class B to Class A common shares outstanding                                                                                                   |           |            |   |   |   |   |   |   | 0 | 0 | 0 |
| Effect of derivative instrument that may settled in cash or shares                                                                                           |           |            |   |   |   |   |   |   | 0 |   |   |
| Effect of share based compensation that may be settled in cash or shares                                                                                     |           |            |   |   |   |   |   |   | 0 |   |   |
| Unexercised stock options                                                                                                                                    |           |            |   |   |   |   |   |   |   | 0 | 0 |
| Number of shares used in per share computation                                                                                                               |           |            |   |   |   |   |   |   | 3,154 | 3,157 | 3,162 |
| Diluted net income (loss) attributable to General Communication, Inc. common stockholders per common share (USD per share)                                   |           |            |   |   |   |   |   |   | $ (0.15) | $ (0.69) | $ 0.18 |

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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 (loss) 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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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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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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| - 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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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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