Investments - Schedule of Available-for-sale Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost	$ 52,215	$ 47,415
Gross Unrealized Gains	259	39
Gross Unrealized Losses	(14)	(17)
Fair Value	52,460	47,437
Certificates of deposit
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost	6,381	5,646
Gross Unrealized Gains	28	17
Gross Unrealized Losses	0	0
Fair Value	6,409	5,663
U.S. Treasury securities
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost	20,583	12,564
Gross Unrealized Gains	183	16
Gross Unrealized Losses	0	(1)
Fair Value	20,766	12,579
U.S. Agency securities
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost	6,527	4,002
Gross Unrealized Gains	21	0
Gross Unrealized Losses	0	(4)
Fair Value	6,548	3,998
Commercial paper
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost	1,996	2,492
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	(1)
Fair Value	1,997	2,491
Corporate notes and bonds
Debt and Equity Securities, FV-NI [Line Items]
Amortized Cost	16,728	22,711
Gross Unrealized Gains	26	6
Gross Unrealized Losses	(14)	(11)
Fair Value	$ 16,740	$ 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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