Marketable Securities - Schedule of Available-for-sale Marketable Securities and Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Cash and cash equivalents:
Amortized Cost Value	$ 81,830	$ 69,886
Fair Value	81,830	69,886
Marketable securities:
Amortized Cost Value	43,790	91,012
Gross Unrealized Gains	91	9
Gross Unrealized Losses	(8)	(6)
Fair Value	43,873	91,015
Cash
Cash and cash equivalents:
Amortized Cost Value	55,796	34,726
Fair Value	55,796	34,726
Money market funds
Cash and cash equivalents:
Amortized Cost Value	26,034	35,160
Fair Value	26,034	35,160
Domestic corporate debt securities
Marketable securities:
Amortized Cost Value	38,822	41,229
Gross Unrealized Gains	91	3
Gross Unrealized Losses	(3)	(3)
Fair Value	38,910	41,229
Domestic corporate commercial paper
Marketable securities:
Amortized Cost Value	4,968	24,900
Gross Unrealized Gains	0	5
Gross Unrealized Losses	(5)	0
Fair Value	$ 4,963	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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