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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 808
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479402/808-10-50-1

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 730
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482916/730-10-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 912
-SubTopic 730
-Name Accounting Standards Codification
-Section 25
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482517/912-730-25-1

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-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481283/985-20-50-1

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+ References

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- Definition

The amount of costs incurred related to the payment of specified development milestones under the agreement.

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- Definition

The number of initial licensed products or services for which the entity is obligated to pay specified amount per licensed product or service under the agreement.

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No definition available.

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The amount of regulatory milestone payments payable for each licensed product upon achievement of specified milestones under the agreement.

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The amount of upfront payments payable under the agreement.

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Number of shares of stock issued during the period pursuant to arrangement.

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Collaboration Agreements and Intellectual Property Licenses - Intellectual Property Licenses (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2016 USD ($) item shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2020 USD ($)	Sep. 30, 2016 USD ($)
Agreements
Research and development		$ 52,136	$ 59,201
License Agreement \| AskGene
Agreements
Upfront payments payable				$ 6,000
Research and development				6,000
License Agreement \| AskGene \| Maximum \| IL-2 products
Agreements
Regulatory milestone payments payable				$ 13,000
License Agreement \| City of Hope
Agreements
Number of shares of common stock issued \| shares	24,019
Number of licensed products or services \| item	3
Costs incurred related to payment of specified development milestones		0	0
License Agreement \| City of Hope \| Maximum
Agreements
Development and regulatory milestones payable per product or licensed service	$ 10,300
License Agreement \| WuXi Biologics
Agreements
Development and regulatory milestones payable per product or licensed service					$ 25,800
Costs incurred related to payment of specified development milestones		$ 0	$ 0