| Basis of Presentation (Details) $ in Millions | 12 Months Ended | ||||
|---|---|---|---|---|---|
| Dec. 10, 2014 | Oct. 29, 2014 | Dec. 31, 2017  USD ($) | Dec. 31, 2016  USD ($) | May 18, 2016 | |
| Broadband Spin-Off Distribution Ratio | 0.25 | ||||
| Charter | |||||
| Voting interest acquired (as a percent) | 25.01% | ||||
| Liberty | |||||
| Related Party Transaction, Amounts of Transaction | $ 3.2 | $ 3.4 | |||
| Series C common stock | |||||
| Subscription rights distribution ratio | 0.20 | ||||
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- Definition Broadband Spin-Off Distribution Ratio No definition available. 
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- Definition Represents the subscription rights distribution ratio. No definition available. 
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- Definition Percentage of voting equity interests acquired at the acquisition date in the business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Amount of transactions with related party during the financial reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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