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v3.21.1

Related Parties - Additional Information (Detail) - USD ($) $ in Millions |  | 3 Months Ended |
--- | --- | --- | ---
May 08, 2020 | Mar. 31, 2021 | Jan. 10, 2020
Mosaic |  |  |
Related Party Transaction [Line Items] |  |  |
Expenses related to collaboration | $ 0.8 |  |
Mosaic | Maximum |  |  |
Related Party Transaction [Line Items] |  |  |
Milestone payments , clinical development events |  | $ 4.0 |
License and Collaboration Agreement (the “Biogen Agreement”) |  |  |
Related Party Transaction [Line Items] |  |  |
Upfront license fee received from collaboration agreement |  |  | $ 15.0

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- Definition Milestone payment . + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Definition Upfront fee reveived from license and collaboration agreement. + References No definition available. + Details
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Namespace Prefix: | cbio_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 + Details
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Balance Type: | debit
Period Type: | duration

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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. + References No definition available. + Details
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- Details
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- Details
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- Details
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