Long-Term Debt (Debt Securities That Are Not Reported At Fair Value) (Details) - USD ($) $ in Millions |
Mar. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Debt Instrument [Line Items] | ||
| Long-term Debt, Fair Value | $ 0 | $ 868 |
| Senior Debentures | ||
| Debt Instrument [Line Items] | ||
| Fair Value of Debt Securities That Are Not Reported at Fair Value | 866 | |
| QVC Senior Secured Notes | ||
| Debt Instrument [Line Items] | ||
| Fair Value of Debt Securities That Are Not Reported at Fair Value | $ 3,569 |