Investments, Available-for-Sale - Schedule of Cost, Gross Unrealized Holding Gains, Gross Unrealized Holding Losses and Fair Value of Available for Sale Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Short-term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 10,975	$ 215,185
Unrealized Gains	0	0
Unrealized Losses	(2)	(31)
Estimated Fair Value	10,973	215,154
Long Term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	43,487
Unrealized Gains	0
Unrealized Losses	(101)
Estimated Fair Value	43,386
U.S. Treasury Securities \| Short-term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	10,014	215,185
Unrealized Gains	0	0
Unrealized Losses	(1)	(31)
Estimated Fair Value	10,013	$ 215,154
U.S. Treasury Securities \| Long Term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	42,517
Unrealized Gains	0
Unrealized Losses	(98)
Estimated Fair Value	42,419
Certificates of Deposit \| Short-term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	961
Unrealized Gains	0
Unrealized Losses	(1)
Estimated Fair Value	960
Certificates of Deposit \| Long Term Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	970
Unrealized Gains	0
Unrealized Losses	(3)
Estimated Fair Value	$ 967

Amount, before tax, of unrealized gain 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).

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Amount, before tax, of unrealized 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).

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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).

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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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