Goodwill and Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Definite-lived intangible assets | ||
| Gross carrying amount | $ 27,345 | $ 23,737 |
| Accumulated amortization | (8,696) | (7,424) |
| Net carrying amount | 18,649 | 16,313 |
| Indefinite-lived research and development | 0 | 4,920 |
| Total intangible assets gross carrying amount | 27,345 | 28,657 |
| Total intangible assets, net | 18,649 | 21,233 |
| Developed product rights | ||
| Definite-lived intangible assets | ||
| Gross carrying amount | 19,547 | 15,872 |
| Accumulated amortization | (6,405) | (5,614) |
| Net carrying amount | 13,142 | 10,258 |
| License agreements | ||
| Definite-lived intangible assets | ||
| Gross carrying amount | 7,798 | 7,865 |
| Accumulated amortization | (2,291) | (1,810) |
| Net carrying amount | $ 5,507 | $ 6,055 |