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Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands | Jun. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Financial assets: |  |
Total financial assets | $ 609,238 | $ 694,495
Financial liabilities: |  |
Success payment liabilities | 3,753 | 4,356
Total financial liabilities | 3,753 | 4,356
U.S. Treasury securities |  |
Financial assets: |  |
Marketable securities | 291,289 | 271,799
U.S. government agency securities |  |
Financial assets: |  |
Marketable securities | 94,511 | 134,045
Corporate debt securities |  |
Financial assets: |  |
Marketable securities | 106,468 | 220,681
Money market funds |  |
Financial assets: |  |
Money market funds | 116,970 | 67,970
Level 1 |  |
Financial assets: |  |
Total financial assets | 116,970 | 67,970
Financial liabilities: |  |
Success payment liabilities | 0 | 0
Total financial liabilities | 0 | 0
Level 1 | U.S. Treasury securities |  |
Financial assets: |  |
Marketable securities | 0 | 0
Level 1 | U.S. government agency securities |  |
Financial assets: |  |
Marketable securities | 0 | 0
Level 1 | Corporate debt securities |  |
Financial assets: |  |
Marketable securities | 0 | 0
Level 1 | Money market funds |  |
Financial assets: |  |
Money market funds | 116,970 | 67,970
Level 2 |  |
Financial assets: |  |
Total financial assets | 492,268 | 626,525
Financial liabilities: |  |
Success payment liabilities | 0 | 0
Total financial liabilities | 0 | 0
Level 2 | U.S. Treasury securities |  |
Financial assets: |  |
Marketable securities | 291,289 | 271,799
Level 2 | U.S. government agency securities |  |
Financial assets: |  |
Marketable securities | 94,511 | 134,045
Level 2 | Corporate debt securities |  |
Financial assets: |  |
Marketable securities | 106,468 | 220,681
Level 2 | Money market funds |  |
Financial assets: |  |
Money market funds | 0 | 0
Level 3 |  |
Financial assets: |  |
Total financial assets | 0 | 0
Financial liabilities: |  |
Success payment liabilities | 3,753 | 4,356
Total financial liabilities | 3,753 | 4,356
Level 3 | U.S. Treasury securities |  |
Financial assets: |  |
Marketable securities | 0 | 0
Level 3 | U.S. government agency securities |  |
Financial assets: |  |
Marketable securities | 0 | 0
Level 3 | Corporate debt securities |  |
Financial assets: |  |
Marketable securities | 0 | 0
Level 3 | Money market funds |  |
Financial assets: |  |
Money market funds | $ 0 | $ 0

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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 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 + Details
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- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References No definition available. + Details
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