Basis of Presentation and Summary of Significant Accounting Policies - Accounting for Share-Based Compensation (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Basis of Presentation | ||||
| Share-based compensation expense | $ 29,026 | $ 14,746 | $ 53,275 | $ 32,579 |
| XOMA Acquisition | ||||
| Basis of Presentation | ||||
| Share-based compensation expense | 10,845 | 10,845 | ||
| Ligand | ||||
| Basis of Presentation | ||||
| Share-based compensation expense | 18,181 | 14,746 | 42,430 | 32,579 |
| Location, Statement of Income, Balance [Axis]: us-gaap:GeneralAndAdministrativeExpense | Ligand | ||||
| Basis of Presentation | ||||
| Share-based compensation expense | 16,895 | 13,516 | 39,117 | 29,490 |
| Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense | Ligand | ||||
| Basis of Presentation | ||||
| Share-based compensation expense | $ 1,286 | $ 1,230 | $ 3,313 | $ 3,089 |