Investments - Schedule of Available-for-sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost	$ 20,600	$ 32,110
Gross Unrealized Gains	2	22
Gross Unrealized Losses	(3)	(1)
Fair Value	20,599	32,131
Certificates of deposit
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost	1,567	5,820
Gross Unrealized Gains	0	5
Gross Unrealized Losses	0	0
Fair Value	1,567	5,825
U.S. Treasury securities
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost		5,908
Gross Unrealized Gains		15
Gross Unrealized Losses		0
Fair Value		5,923
Commercial paper
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost	8,267	10,603
Gross Unrealized Gains	2	1
Gross Unrealized Losses	0	0
Fair Value	8,269	10,604
Corporate notes and bonds
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost	10,766	9,779
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(3)	(1)
Fair Value	$ 10,763	$ 9,779

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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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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