Fair Value Measurement (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Financial Assets and Liabilities Measured at Fair Value on Recurring Basis

The following tables sets forth the fair value of the Company’s financial assets and liabilities at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands):

	June 30, 2018
	Level 1		Level 2		Level 3		Total
Financial Assets
Money market funds	$	6,807	$	—	$	—	$	6,807
Reverse repurchase agreements		—		6,250		—		6,250
Commercial paper		—		31,925		—		31,925
U.S. government securities		—		25,680		—		25,680
Total financial assets	$	6,807	$	63,855	$	—	$	70,662

	December 31, 2017
	Level 1		Level 2		Level 3		Total
Financial Assets
Money market funds	$	1,674	$	—	$	—	$	1,674
Reverse repurchase agreements		—		7,250		—		7,250
U.S. treasury securities		1,501		—		—		1,501
U.S. government securities		—		35,981		—		35,981
Total financial assets	$	3,175	$	43,231	$	—	$	46,406