Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Summary of Assets Measured at Fair Value on a Recurring Basis

The following tables show assets measured at fair value on a recurring basis as of March 31, 2018 and December 31, 2017:

	March 31, 2018
(in thousands)	Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	6,785	$	—	$	—
Corporate debt securities		—		2,009		—
Commercial paper		—		13,781		—
Totals	$	6,785	$	15,790	$	—
Marketable securities:
Corporate debt securities	$	—	$	6,217	$	—
Commercial paper		—		21,841		—
Government securities		—		13,940		—
Totals	$	—	$	41,998	$	—

	December 31, 2017
(in thousands)	Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	89,310	$	—	$	—
Totals	$	89,310	$	—	$	—