Related Party Transactions (Narrative) (Details) - USD ($) $ in Millions |
Mar. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Other noncurrent liabilities | $ 10,431 | $ 10,637 |
| NBCUniversal Media LLC [Member] | ||
| Other noncurrent liabilities | 3,890 | $ 3,790 |
| Carrying Value Of Related Party Contractual Obligation [Member] | NBCUniversal Media LLC [Member] | ||
| Other noncurrent liabilities | $ 383 |