Sanofi License and Collaboration Agreement - Additional Information (Details) $ in Millions	Jul. 31, 2019 USD ($)
Termination Agreement \| Royalty Rights \| Sanofi (Aventis Inc.)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount Payable to reacquire research and development asset	$ 80.0

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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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration