Fair Value Measurements - Available For Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair value of available for sale marketable securities
Amortized Cost	$ 38,500	$ 72,799
Gross Unrealized Gains	55	37
Gross Unrealized Losses	(2)	(8)
Fair Value	38,553	72,828
U.S. Treasury securities
Fair value of available for sale marketable securities
Amortized Cost	3,025	7,019
Gross Unrealized Gains	4	4
Fair Value	3,029	7,023
U.S. Government agency securities
Fair value of available for sale marketable securities
Amortized Cost	24,481	17,701
Gross Unrealized Gains	24	16
Gross Unrealized Losses	(2)
Fair Value	24,503	17,717
Corporate debt obligations
Fair value of available for sale marketable securities
Amortized Cost	10,994	48,079
Gross Unrealized Gains	27	17
Gross Unrealized Losses		(8)
Fair Value	$ 11,021	$ 48,088

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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Amount, before tax, of unrealized loss 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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Amortized cost of 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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