Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table presents our fair value hierarchy for assets measured at fair value on a recurring basis as of June 30, 2018 and December 31, 2017 (in thousands):



	Fair value as of June 30, 2018
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	11,464	$	11,464	$	—	$	—
Corporate debt securities	10,000		—		10,000		—
Certificates of deposit	3,890		—		3,890		—
U.S. treasury securities	3,984		—		3,984		—
Debt securities of U.S. government-sponsored agencies	1,497		—		1,497		—
	$	30,835	$	11,464	$	19,371	$	—



	Fair value as of December 31, 2017
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	10,847	$	10,847	$	—	$	—
Corporate debt securities	32,867		—		32,867		—
Certificates of deposit	8,216		—		8,216		—
U.S. treasury securities	3,978		—		3,978		—
Debt securities of U.S. government-sponsored agencies	1,494		—		1,494		—
	$	57,402	$	10,847	$	46,555	$	—