Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Quoted prices in Active Market for Identical Assets (Level 1) \| Money market funds
Financial assets:
Money market funds	$ 55,275	$ 133,583
Quoted prices in Active Market for Identical Assets (Level 1) \| U.S. Treasury debt securities
Financial assets:
Investment	119,232	80,444
Significant Other Observable Inputs (Level 2) \| Municipal securities
Financial assets:
Investment	19,661	27,004
Significant Other Observable Inputs (Level 2) \| Corporate debt securities
Financial assets:
Investment	188,643	251,267
Significant Other Observable Inputs (Level 2) \| Commercial Paper
Financial assets:
Investment	197,964	224,276
Fair Value Measurements Recurring
Financial assets:
Total financial assets measured at fair value on a recurring basis	580,775	716,574
Financial liabilities:
Total financial liabilities measured at fair value on a recurring basis	9,928	24,168
Fair Value Measurements Recurring \| Stock price appreciation milestones
Financial liabilities:
Stock price appreciation milestones	9,928	24,168
Fair Value Measurements Recurring \| Money market funds
Financial assets:
Money market funds	55,275	133,583
Fair Value Measurements Recurring \| U.S. Treasury debt securities
Financial assets:
Investment	119,232	80,444
Fair Value Measurements Recurring \| Municipal securities
Financial assets:
Investment	19,661	27,004
Fair Value Measurements Recurring \| Corporate debt securities
Financial assets:
Investment	188,643	251,267
Fair Value Measurements Recurring \| Commercial Paper
Financial assets:
Investment	197,964	224,276
Fair Value Measurements Recurring \| Quoted prices in Active Market for Identical Assets (Level 1)
Financial assets:
Total financial assets measured at fair value on a recurring basis	174,507	214,027
Fair Value Measurements Recurring \| Significant Other Observable Inputs (Level 2)
Financial assets:
Total financial assets measured at fair value on a recurring basis	406,268	502,547
Fair Value Measurements Recurring \| Significant Unobservable Inputs (Level 3)
Financial liabilities:
Total financial liabilities measured at fair value on a recurring basis	9,928	24,168
Fair Value Measurements Recurring \| Significant Unobservable Inputs (Level 3) \| Stock price appreciation milestones
Financial liabilities:
Stock price appreciation milestones	$ 9,928	$ 24,168

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

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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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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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Fair value of financial and nonfinancial obligations.

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