Segment, Geographic and Other Revenue Information - Revenues By Geographic Area (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Revenues from External Customers and Long-Lived Assets [Line Items] | |||
| Revenues | $ 51,750 | $ 53,647 | $ 52,546 |
| United States [Member] | |||
| Revenues from External Customers and Long-Lived Assets [Line Items] | |||
| Revenues | 23,852 | 25,329 | 26,026 |
| Developed Europe [Member] | |||
| Revenues from External Customers and Long-Lived Assets [Line Items] | |||
| Revenues | 8,701 | 9,116 | 8,508 |
| Developed Rest Of World [Member] | |||
| Revenues from External Customers and Long-Lived Assets [Line Items] | |||
| Revenues | 6,465 | 6,551 | 6,612 |
| Emerging Markets [Member] | |||
| Revenues from External Customers and Long-Lived Assets [Line Items] | |||
| Revenues | $ 12,733 | $ 12,651 | $ 11,399 |