Reportable Segments (Schedule Of Total Assets By Segment) (Details) - USD ($) $ in Millions |
Jun. 30, 2017 |
Dec. 31, 2016 |
---|---|---|
Segment Reporting Information [Line Items] | ||
Total assets | $ 16,149 | $ 15,672 |
U.S. Networks [Member] | ||
Segment Reporting Information [Line Items] | ||
Total assets | 3,598 | 3,412 |
International Networks [Member] | ||
Segment Reporting Information [Line Items] | ||
Total assets | 5,205 | 4,922 |
Education And Other [Member] | ||
Segment Reporting Information [Line Items] | ||
Total assets | 376 | 399 |
Corporate And Inter-Segment Eliminations [Member] | ||
Segment Reporting Information [Line Items] | ||
Total assets | $ 6,970 | $ 6,939 |