Changes in Carrying Amount of Goodwill (Detail) $ in Millions |
3 Months Ended |
|---|---|
|
Mar. 31, 2017
USD ($)
| |
| Goodwill [Line Items] | |
| Beginning balance | $ 27,205 |
| Acquisitions (Note 2) | 420 |
| Reclassifications, adjustments and other | 5 |
| Ending balance | 27,630 |
| Wireless | |
| Goodwill [Line Items] | |
| Beginning balance | 18,393 |
| Ending balance | 18,393 |
| Wireline | |
| Goodwill [Line Items] | |
| Beginning balance | 3,784 |
| Acquisitions (Note 2) | 418 |
| Reclassifications, adjustments and other | 3 |
| Ending balance | 4,205 |
| Other Operating Segments | |
| Goodwill [Line Items] | |
| Beginning balance | 5,028 |
| Acquisitions (Note 2) | 2 |
| Reclassifications, adjustments and other | 2 |
| Ending balance | $ 5,032 |