Share-Based Compensation (Recognized Share-Based Compensation Expense) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2015 |
Sep. 30, 2014 |
Sep. 30, 2015 |
Sep. 30, 2014 |
|
| Recognized share-based compensation expense | $ 113 | $ 98 | $ 343 | $ 310 |
| NBCUniversal Media, LLC [Member] | ||||
| Recognized share-based compensation expense | 24 | 20 | 74 | 70 |
| Stock Options [Member] | ||||
| Recognized share-based compensation expense | 40 | 38 | 118 | 121 |
| Stock Options [Member] | NBCUniversal Media, LLC [Member] | ||||
| Recognized share-based compensation expense | 3 | 4 | 8 | 13 |
| Restricted Share Units [Member] | ||||
| Recognized share-based compensation expense | 67 | 55 | 205 | 171 |
| Restricted Share Units [Member] | NBCUniversal Media, LLC [Member] | ||||
| Recognized share-based compensation expense | 20 | 15 | 61 | 52 |
| Employee Stock Purchase Plan [Member] | ||||
| Recognized share-based compensation expense | 6 | 5 | 20 | 18 |
| Employee Stock Purchase Plan [Member] | NBCUniversal Media, LLC [Member] | ||||
| Recognized share-based compensation expense | $ 1 | $ 1 | $ 5 | $ 5 |