|
Changes in Carrying Amount of Goodwill (Detail) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2015
|
Dec. 31, 2014
|
|
| Goodwill [Line Items] | ||
| Beginning balance | $ 24,639 | |
| Reclassifications, adjustments and other | (1,336) | |
| Ending balance | 23,303 | |
| Wireless | ||
| Goodwill [Line Items] | ||
| Beginning balance | 18,390 | |
| Ending balance | 18,390 | 18,390 |
| Wireline | ||
| Goodwill [Line Items] | ||
| Beginning balance | 6,249 | |
| Reclassifications, adjustments and other | (1,336) | |
| Ending balance | $ 4,913 |