Segment reporting - Product net sales by country of sales (Details) - USD ($) $ in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Segment reporting | ||
| Total product net sales | $ 2,813 | $ 1,739 |
| United States | ||
| Segment reporting | ||
| Total product net sales | 2,380 | 1,483 |
| Japan | ||
| Segment reporting | ||
| Total product net sales | 169 | 84 |
| China | ||
| Segment reporting | ||
| Total product net sales | 17 | 33 |
| Rest of the World | ||
| Segment reporting | ||
| Total product net sales | $ 247 | $ 139 |