The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 730
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6420194&loc=d3e21568-108373

Name:	us-gaap_ResearchAndDevelopmentExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

License and Collaboration Agreements - Summary of Research and Development Costs Related to Collaboration and License Agreements (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Jan. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development costs		$ 12,415	$ 4,173
Collaboration and License Agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development costs		3,000	240
Collaboration and License Agreements \| Cullinan Management - Adimab
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development costs			104
Collaboration and License Agreements \| Apollo - Wistar
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development costs			$ 136
Collaboration and License Agreements \| Pearl - Taiho
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research and development costs	$ 3,000	$ 3,000