Marketable Securities - Schedule of Available-for-sale Marketable Securities and Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Cash and cash equivalents:
Amortized Cost Value	$ 40,723	$ 69,886
Fair Value	40,723	69,886
Marketable securities:
Amortized Cost Value	97,923	91,012
Gross Unrealized Gains	26	9
Gross Unrealized Losses	(692)	(6)
Fair Value	97,257	91,015
Domestic corporate debt securities
Marketable securities:
Amortized Cost Value	68,115	41,229
Gross Unrealized Gains	0	3
Gross Unrealized Losses	(638)	(3)
Fair Value	67,477	41,229
Domestic corporate commercial paper
Marketable securities:
Amortized Cost Value	17,410	24,900
Gross Unrealized Gains	5	5
Gross Unrealized Losses	(54)
Fair Value	17,361	24,905
Agency bonds
Marketable securities:
Amortized Cost Value	12,398	12,391
Gross Unrealized Gains	21	1
Gross Unrealized Losses	0	(3)
Fair Value	12,419	12,389
US treasury bonds
Marketable securities:
Amortized Cost Value		12,492
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		12,492
Cash
Cash and cash equivalents:
Amortized Cost Value	21,949	34,726
Fair Value	21,949	34,726
Money market funds
Cash and cash equivalents:
Amortized Cost Value	18,774	35,160
Fair Value	$ 18,774	$ 35,160

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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