Changes in Carrying Amount of Goodwill (Detail) $ in Millions |
3 Months Ended |
|---|---|
|
Mar. 31, 2016
USD ($)
| |
| Goodwill [Line Items] | |
| Beginning balance | $ 25,331 |
| Acquisitions (Note 2) | 31 |
| Reclassifications, adjustments and other | 2 |
| Ending balance | 25,364 |
| Wireless | |
| Goodwill [Line Items] | |
| Beginning balance | 18,393 |
| Ending balance | 18,393 |
| Wireline | |
| Goodwill [Line Items] | |
| Beginning balance | 4,331 |
| Reclassifications, adjustments and other | 1 |
| Ending balance | 4,332 |
| Other Operating Segments | |
| Goodwill [Line Items] | |
| Beginning balance | 2,607 |
| Acquisitions (Note 2) | 31 |
| Reclassifications, adjustments and other | 1 |
| Ending balance | $ 2,639 |