Fair Value of Investments (Tables)

9 Months Ended

Sep. 30, 2019

Fair Value of Investments

Summary of fair value financial assets measured on a recurring basis

	(Level 1)		(Level 2)		(Level 3)		Total
September 30, 2019
Assets:
Money market funds	$	16,602	$	—	$	—	$	16,602
U.S. government securities		9,985		—		—		9,985
Corporate bonds		—		17,791		—		17,791
Commercial paper		—		31,437		—		31,437
Asset-backed securities		—		16,299		—		16,299
Total assets	$	26,587	$	65,527	$	—	$	92,114
	(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