Investments and Fair-Value Measurements - Fair value of investments (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Fair Value of investment [Line items]
Investment income, interest	$ 4,200	$ 200	$ 7,600	$ 200
Amortized cost, current	334,680		334,680		$ 183,909
Amortized cost, total	335,734		335,734		184,963
Gross unrealized gains (losses)	(89)		(89)		22
Estimated Fair Value, Current	334,591		334,591		183,931
Estimated Fair Value, total	335,645		335,645		184,985
US Treasury Securities
Fair Value of investment [Line items]
Amortized cost, current	225,983		225,983		99,027
Gross unrealized gains (losses)	(89)		(89)		22
Estimated Fair Value, Current	225,894		225,894		99,049
Money Market Funds
Fair Value of investment [Line items]
Amortized cost, current	108,697		108,697		84,882
Estimated Fair Value, Current	108,697		108,697		84,882
Certificates of Deposit [Member]
Fair Value of investment [Line items]
Amortized cost, noncurrent	1,054		1,054		1,054
Estimated Fair Value, Noncurrent	$ 1,054		$ 1,054		$ 1,054

Fair Value of Investment [Line Items]

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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), classified as current.

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Amount, before tax, of unrealized gain (loss) in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current.

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Amortized cost, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) and 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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Fair value of investment in debt security measured at amortized cost (held-to-maturity) and 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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Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity), classified as current.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), classified as noncurrent.

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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

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