Collaborations and Licensing Agreements - Additional Information (Details) $ / shares in Units, $ in Millions			3 Months Ended
	Aug. 07, 2021 USD ($) $ / shares shares	Jan. 01, 2011 Optiontarget	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jul. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Regulatory milestone payments obligation					$ 0.9
Reimbursements receivable of regulatory milestone					$ 1.0
Roche [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Regulatory milestone payments obligation						$ 1.0
Notice period in days			90 days
HutchMed License Agreement [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Percentage cost incurred for global studies and total number of patients enrolled In the territory	20.00%
Percentage cost incurred for global studies not specific to any territory	20.00%
Development and regulatory milestone payment	$ 110.0
Royalties payable for licensed product, description	Royalties are payable for each Licensed Product commencing on the first commercial sale of the applicable Licensed Product and ending, on a Jurisdiction-by-Jurisdiction basis, on the latest of expiration of specified patent coverage, expiration of specified regulatory exclusivity or a specified period following the first commercial sale in such Jurisdiction and may be reduced in various circumstances.
Clinical license agreement expiration terms	HutchMed License Agreement will expire upon the expiration of the last royalty term for the last Licensed Product in the Field in the Territory. HutchMed may terminate the HutchMed License Agreement in its entirety for any or no reason upon 12 months’ prior written notice to the Company.
Upfront milestone			$ 13.0
Nonrefundable upfront payment received	$ 25.0
HutchMed License Agreement [Member] | License Revenue [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Total revenue			12.0
HutchMed License Agreement [Member] | Common Stock [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Date prior to which warrants are exercisable	Aug. 07, 2025
Number of securities into which the class of warrant or right may be converted | shares	5,653,000
Exercise price of warrants | $ / shares	$ 11.50
HutchMed License Agreement [Member] | Maximum [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Sales milestone payment	$ 175.0
GSK [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Number of option targets | Optiontarget		3
Eisai [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Research and development reduction				$ 0.4
Obligation related to World Wide Royalty			1.3	0.9
Other Receivables			0.1	0.1
Royalties payable			1.3	0.9
Eisai [Member] | Tazemetostat Drug Pruducts [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Deferred revenue				5.0
Total revenue				$ 1.3
Royalty Pharma and Pharmakon Advisors [Member] | Roche [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Remaining unpaid milestone payments			1.0				$ 10.4
Reimbursements receivable of development costs			$ 0.9
Signed Amendment [Member] | Roche [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Regulatory milestone payments obligation						0.5
Fourth Amendment [Member] | Roche [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Regulatory milestone payments obligation						$ 0.5