Fair Value Measurements - Financial Instruments Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Cash and cash equivalents	$ 193,705	$ 224,947
Common stock in LianBio	46	631
Equity warrants (for LianBio shares)		225
Total assets measured at fair value	298,524	228,298
Money market funds
Assets:
Cash and cash equivalents	186,744	224,947
U.S. Treasury securities
Assets:
Cash and cash equivalents	3,484
Debt securities, available for sale and cash and cash equivalents	31,812
Commercial paper
Assets:
Cash and cash equivalents	3,477
Debt securities, available for sale and cash and cash equivalents	30,828
Corporate debt securities
Assets:
Debt securities, available for sale and cash and cash equivalents	25,490
Government-related debt securities
Assets:
Debt securities, available for sale and cash and cash equivalents	23,604	2,495
Level 1
Assets:
Common stock in LianBio	46	631
Equity warrants (for LianBio shares)		0
Total assets measured at fair value	218,602	225,578
Level 1 \| Money market funds
Assets:
Cash and cash equivalents	186,744	224,947
Level 1 \| U.S. Treasury securities
Assets:
Debt securities, available for sale and cash and cash equivalents	31,812
Level 1 \| Commercial paper
Assets:
Debt securities, available for sale and cash and cash equivalents	0
Level 1 \| Corporate debt securities
Assets:
Debt securities, available for sale and cash and cash equivalents	0
Level 1 \| Government-related debt securities
Assets:
Debt securities, available for sale and cash and cash equivalents	0	0
Level 2
Assets:
Common stock in LianBio	0	0
Equity warrants (for LianBio shares)		0
Total assets measured at fair value	79,922	2,495
Level 2 \| Money market funds
Assets:
Cash and cash equivalents	0	0
Level 2 \| U.S. Treasury securities
Assets:
Debt securities, available for sale and cash and cash equivalents	0
Level 2 \| Commercial paper
Assets:
Debt securities, available for sale and cash and cash equivalents	30,828
Level 2 \| Corporate debt securities
Assets:
Debt securities, available for sale and cash and cash equivalents	25,490
Level 2 \| Government-related debt securities
Assets:
Debt securities, available for sale and cash and cash equivalents	23,604	2,495
Level 3
Assets:
Common stock in LianBio	0	0
Equity warrants (for LianBio shares)		225
Total assets measured at fair value	0	225
Level 3 \| Money market funds
Assets:
Cash and cash equivalents	0	0
Level 3 \| U.S. Treasury securities
Assets:
Debt securities, available for sale and cash and cash equivalents	0
Level 3 \| Commercial paper
Assets:
Debt securities, available for sale and cash and cash equivalents	0
Level 3 \| Corporate debt securities
Assets:
Debt securities, available for sale and cash and cash equivalents	0
Level 3 \| Government-related debt securities
Assets:
Debt securities, available for sale and cash and cash equivalents	$ 0	$ 0

Debt Securities, Available-For-Sale And Cash And Cash Equivalents

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Equity Warrants, Fair Value Disclosure

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
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-Section 50
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- Definition

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(b))
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-Publisher FASB
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-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482736/825-10-45-1A

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