Investments (Tables)

6 Months Ended

Jun. 30, 2018

Investments, Debt and Equity Securities [Abstract]

Summary of amortized cost, and gross unrealized gains and losses on all securities

The following table presents the amortized cost and gross unrealized gains and losses on all securities at June 30, 2018:

	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
	(in thousands)
Short-term investments:
U.S. Treasury securities	$	1,499	$	—	$	—		$	1,499
Commercial paper		11,730	$	—		(1	)	$	11,729
Corporate notes / bonds		261		—		—			261
Total short-term investments	$	13,490	$	—	$	(1	)	$	13,489

The following table presents the amortized cost and gross unrealized gains and losses on all securities at December 31, 2017:

	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
	(in thousands)
Short-term investments:
Commercial paper	$	4,994	$	—	$	(1	)	$	4,993
Corporate notes / bonds		1,458		—		—			1,458
Total short-term investments	$	6,452	$	—	$	(1	)	$	6,451

Summary of financial assets measured at fair value on a recurring basis

The following table summarizes the Company’s financial assets measured at fair value on a recurring basis as of June 30, 2018:

	Level 1		Level 2		Level 3		Total
	(in thousands)
Cash equivalents:
Money market funds	$	3,514	$	—	$	—	$	3,514
Investments:
Available-for-sales securities — current:
U.S. Treasury securities		—		1,499		—		1,499
Commercial paper		—		11,729		—		11,729
Corporate notes / bonds		—		261		—		261
Total	$	3,514	$	13,489	$	—	$	17,003

The following table summarizes the Company’s financial assets measured at fair value on a recurring basis as of December 31, 2017:

	Level 1		Level 2		Level 3		Total
	(in thousands)
Cash equivalents:
Money market funds	$	4,575	$	—	$	—	$	4,575
Investments:
Available-for-sales securities — current:
Commercial paper		—		4,993		—		4,993
Corporate notes / bonds		—		1,458		—		1,458
Total	$	4,575	$	6,451	$	—	$	11,026