| Summary of Significant Accounting Policies - Research and Development Expenditure (Details) - USD ($) | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | |
| Summary of Significant Accounting Policies | |||
| Acquired in-process R&D expensed | $ 2,316,000 | $ 562,000 | $ 889,000 | 
| Research and Development Asset Acquired Other than through Business Combination, Writeoff, Statement of Income or Comprehensive Income [Extensible Enumeration] | Research and Development Expense | Research and Development Expense | Research and Development Expense | 
| Reimbursement of Research and Development Tax and Expenditure Credit | $ 30,226,000 | $ 34,082,000 | $ 19,442,000 | 
| X | ||||||||||
| 
- Definition Reimbursement Of research and development tax and expenditure credit. No definition available. 
 | 
| X | ||||||||||
| 
- References No definition available. 
 | 
| X | ||||||||||
| 
- Definition The amount of the write-off for research and development assets that were acquired in a transaction other than a business combination. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 | 
| X | ||||||||||
| 
- Definition Indicates line item in statement of income or comprehensive income that includes writeoff for research and development asset acquired in transaction other than business combination. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
 |