Short-term Investments - Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized cost	$ 262,711	$ 28,800
Gross unrealized gains	19	83
Gross unrealized losses	(43)	0
Fair value	262,687	28,883
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized cost	197,737	22,338
Gross unrealized gains	17	71
Gross unrealized losses	(22)	0
Fair value	197,732	22,409
Government-related debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized cost	33,186	5,000
Gross unrealized gains	0	3
Gross unrealized losses	(12)	0
Fair value	33,174	5,003
Asset-backed Securities
Debt Securities, Available-for-sale [Line Items]
Amortized cost	31,788	1,462
Gross unrealized gains	2	9
Gross unrealized losses	(9)	0
Fair value	$ 31,781	$ 1,471

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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-Section 50
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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).

+ 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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Publisher FASB
-Name Accounting Standards Codification
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