| Long-Term Debt (Debt Securities That Are Not Reported At Fair Value) (Details) $ in Millions | Sep. 30, 2017  USD ($) | 
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| Senior Debentures | |
| Debt Instrument [Line Items] | |
| Fair Value of Debt Securities That Are Not Reported at Fair Value | $ 885 | 
| QVC Senior Secured Notes | |
| Debt Instrument [Line Items] | |
| Fair Value of Debt Securities That Are Not Reported at Fair Value | $ 3,654 | 
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- Definition Fair value of debt securities that are note reported at fair value No definition available. 
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