Collaborative and Other Relationships - Summary of Activity Related to the UCB Collaboration (Details) - Research and development - UCB Pharma S.A. - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Collaborative arrangements and non-collaborative arrangement transactions | ||||
| Expense incurred by the collaboration | $ 17.8 | $ 16.5 | $ 39.6 | $ 33.1 |
| Expense reflected within statements of income | $ 8.9 | $ 8.3 | $ 19.8 | $ 16.6 |