Segment, Geographic and Other Revenue Information - Revenues By Geographic Area - Footnotes (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 |
| Developed Europe [Member] | |||
| Revenues from External Customers and Long-Lived Assets [Line Items] | |||
| Revenues | 8,701 | 9,116 | 8,508 |
| Euro Member Countries, Euro | Developed Europe [Member] | |||
| Revenues from External Customers and Long-Lived Assets [Line Items] | |||
| Revenues | $ 7,000 | $ 7,300 | $ 6,800 |