Marketable Securities - Schedule of Available-for-sale Marketable Securities and Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Cash and cash equivalents:
Amortized Cost Value	$ 56,239	$ 69,886
Fair Value	56,239	69,886
Marketable securities:
Amortized Cost Value	69,387	91,012
Gross Unrealized Gains	203	9
Gross Unrealized Losses	(95)	(6)
Fair Value	69,495	91,015
Cash
Cash and cash equivalents:
Amortized Cost Value	8,616	34,726
Fair Value	8,616	34,726
Money market funds
Cash and cash equivalents:
Amortized Cost Value	47,623	35,160
Fair Value	47,623	35,160
Domestic corporate debt securities
Marketable securities:
Amortized Cost Value	64,443	41,229
Gross Unrealized Gains	203	3
Gross Unrealized Losses	(29)	(3)
Fair Value	64,617	41,229
Domestic corporate commercial paper
Marketable securities:
Amortized Cost Value	4,944	24,900
Gross Unrealized Gains	0	5
Gross Unrealized Losses	(66)	0
Fair Value	$ 4,878	24,905
Agency bonds
Marketable securities:
Amortized Cost Value		12,391
Gross Unrealized Gains		1
Gross Unrealized Losses		(3)
Fair Value		12,389
US treasury bonds
Marketable securities:
Amortized Cost Value		12,492
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		$ 12,492

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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