Summary of Significant Accounting Policies - Research and Development Expenditure (Details) - USD ($) |
12 Months Ended | ||
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Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
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| Summary of Significant Accounting Policies | |||
| Acquired in-process R&D expensed | $ 889,000 | $ 4,556,000 | $ 210,000 |
| Reimbursement of Research and Development Tax and Expenditure Credit | $ 19,442,000 | $ 18,649,000 | $ 17,299,000 |
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- Definition Reimbursement Of research and development tax and expenditure credit. No definition available.
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- References No definition available.
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- 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
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