Goodwill and Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Millions |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Definite-lived intangible assets | ||
| Gross carrying amount | $ 95,535 | $ 27,345 |
| Accumulated amortization | (14,536) | (8,696) |
| Net carrying amount | 80,999 | 18,649 |
| Indefinite-lived research and development | 1,877 | 0 |
| Total intangible assets gross carrying amount | 97,412 | 27,345 |
| Total intangible assets, net | 82,876 | 18,649 |
| Developed product rights | ||
| Definite-lived intangible assets | ||
| Gross carrying amount | 87,707 | 19,547 |
| Accumulated amortization | (11,620) | (6,405) |
| Net carrying amount | 76,087 | 13,142 |
| License agreements | ||
| Definite-lived intangible assets | ||
| Gross carrying amount | 7,828 | 7,798 |
| Accumulated amortization | (2,916) | (2,291) |
| Net carrying amount | $ 4,912 | $ 5,507 |