Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financial assets:
Equity warrant investment		$ 1,067
Total financial assets	$ 694,495	875,800
Financial liabilities:
Success payment liabilities	4,356	9,486
Total financial liabilities	4,356	9,486
U.S. Treasury securities
Financial assets:
Marketable securities	271,799	289,706
U.S. government agency securities
Financial assets:
Marketable securities	134,045	93,626
Corporate debt securities
Financial assets:
Marketable securities	220,681	285,156
Money market funds
Financial assets:
Cash and cash equivalents	67,970	206,245
Level 1
Financial assets:
Equity warrant investment		0
Total financial assets	67,970	206,245
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:
Cash and cash equivalents	67,970	206,245
Level 2
Financial assets:
Equity warrant investment		0
Total financial assets	626,525	668,488
Financial liabilities:
Success payment liabilities	0	0
Total financial liabilities	0	0
Level 2 \| U.S. Treasury securities
Financial assets:
Marketable securities	271,799	289,706
Level 2 \| U.S. government agency securities
Financial assets:
Marketable securities	134,045	93,626
Level 2 \| Corporate debt securities
Financial assets:
Marketable securities	220,681	285,156
Level 2 \| Money market funds
Financial assets:
Cash and cash equivalents	0	0
Level 3
Financial assets:
Equity warrant investment		1,067
Total financial assets	0	1,067
Financial liabilities:
Success payment liabilities	4,356	9,486
Total financial liabilities	4,356	9,486
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:
Cash and cash equivalents	$ 0	$ 0

Success Payment Liabilities, 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

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-Name Accounting Standards Codification
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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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.

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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), classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

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