Long-Term Debt (Debt Securities That Are Not Reported At Fair Value) (Details) $ in Millions |
Sep. 30, 2017
USD ($)
|
|---|---|
| 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 |