| Revenue - Collaboration Agreement - The GSK Collaboration and License Agreement (Details) - GSK Collaboration And License Agreement | 1 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
| Jun. 30, 2021  USD ($) | Dec. 31, 2019  USD ($) | Dec. 19, 2022  USD ($) | Dec. 19, 2022  GBP (£) | |
| Revenue | ||||
| Amount of development milestone achieved | $ 3,200,000 | |||
| Milestone payments received | $ 4,200,000 | |||
| Payment by GSK due to termination of collaboration | £ | £ 5,000,000 | |||
| Aggregate transaction price of the contract modification | $ 6,500,000 | |||
| Payment on contract modification | (6,100,000) | £ 5,000,000 | ||
| Amount of remaining deferred income under the collaboration that had not been recognized as revenue | $ 400,000 | |||
| X | ||||||||||
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- Definition Represents cash received upon achievement of development milestones. No definition available. 
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| X | ||||||||||
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- Definition Represents cash received upon achievement of various development milestones under license agreements. No definition available. 
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| X | ||||||||||
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- Definition Amount of payment due to termination of collaboration. No definition available. 
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| X | ||||||||||
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- Definition Amount aggregate transaction price of the contract modification. No definition available. 
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| X | ||||||||||
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- Definition Amount of payment on the contract modification. No definition available. 
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- 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. No definition available. 
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- Definition Amount of transaction price allocated to performance obligation that has not been recognized as revenue. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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| X | ||||||||||
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- Details 
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