Fair Value of Investments (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value of Investments

Summary of fair value financial assets measured on a recurring basis

	(Level 1)		(Level 2)		(Level 3)		Total
December 31, 2019
Assets:
Money market funds	$	26,812	$	—	$	—	$	26,812
U.S. government securities		4,544		—		—		4,544
Corporate bonds		—		17,754		—		17,754
Commercial paper		—		24,679		—		24,679
Asset-backed securities		—		13,808		—		13,808
Total assets	$	31,356	$	56,241	$	—	$	87,597
	(Level 1)		(Level 2)		(Level 3)		Total
December 31, 2018
Assets:
Money market funds	$	12,947	$	—	$	—	$	12,947
U.S. government securities		15,923		—		—		15,923
Corporate bonds		—		31,495		—		31,495
Commercial paper		—		27,869		—		27,869
Asset-backed securities		—		17,025		—		17,025
Total assets	$	28,870	$	76,389	$	—	$	105,259