| Restructuring - TCR post-acquisition senior leadership severance - Change in Liability (Details) $ in Thousands | 7 Months Ended | 
|---|---|
| Dec. 31, 2023  USD ($) | |
| Restructuring | |
| Beginning liability | $ 805 | 
| Cost paid during the period | (5,887) | 
| Ending liability | 573 | 
| Research and development | |
| Restructuring | |
| Costs incurred and charged | 1,267 | 
| General and administrative | |
| Restructuring | |
| Costs incurred and charged | $ 4,388 | 
| X | ||||||||||
| 
- Definition Amount of cash payments for severance costs relating to employees who are leaving as a result of the acquisition. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Refers to accrued payments for severance costs relating to employees who are leaving as a result of the acquisition. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of restructuring cost. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
 | 
| X | ||||||||||
| 
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
 | 
| X | ||||||||||
| 
- Details 
 | 
| X | ||||||||||
| 
- Details 
 |