Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of assets measured at fair value on recurring basis

The following tables summarize assets that are measured at fair value on a recurring basis:

	March 31, 2019
(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents
Money market funds	$	20,732	$	—	$	—	$	20,732
Commercial paper	—		4,489		—		4,489
	$	20,732	$	4,489	$	—	$	25,221
Short-term investments
Commercial paper	$	—	$	66,166	$	—	$	66,166
Corporate bonds	—		12,678		—		12,678
U.S. Treasury and agency obligations	—		52,170		—		52,170
	$	—	$	131,014	$	—	$	131,014

	December 31, 2018
(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents
Money market funds	$	38,022	$	—	$	—	$	38,022
	$	38,022	$	—	$	—	$	38,022
Short-term investments
Commercial paper	$	—	$	79,634	$	—	$	79,634
Corporate bonds	—		16,119		—		16,119
U.S. Treasury and agency obligations	—		22,366		—		22,366
	$	—	$	118,119	$	—	$	118,119