Investments - Schedule of Available-for-sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Investment [Line Items]
Total	$ 32,110	$ 47,415
Gross Unrealized Gains	22	39
Gross Unrealized Losses	(1)	(17)
Fair Value	32,131	47,437
Certificates of deposit
Investment [Line Items]
Total	5,820	5,646
Gross Unrealized Gains	5	17
Gross Unrealized Losses	0	0
Fair Value	5,825	5,663
US Treasury securities
Investment [Line Items]
Total	5,908	12,564
Gross Unrealized Gains	15	16
Gross Unrealized Losses	0	(1)
Fair Value	5,923	12,579
US Agency securities
Investment [Line Items]
Total		4,002
Gross Unrealized Gains		0
Gross Unrealized Losses		(4)
Fair Value		3,998
Commercial paper
Investment [Line Items]
Total	10,603	2,492
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	(1)
Fair Value	10,604	2,491
Corporate notes and bonds
Investment [Line Items]
Total	9,779	22,711
Gross Unrealized Gains	1	6
Gross Unrealized Losses	(1)	(11)
Fair Value	$ 9,779	$ 22,706

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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