Fair value (Tables)

3 Months Ended

Mar. 31, 2020

Fair value of financial assets and liabilities

Summary of assets that are measured at fair value on a recurring basis

	Fair Value Measurements as of March 31, 2020 Using:
	Total		Level 1		Level 2		Level 3
Money market funds	$	32,733	$	32,733	$	—	$	—
Commercial paper		46,509		—		46,509		—
U.S. treasury securities		12,141		12,141		—		—
Corporate debt securities		19,390		—		19,390		—
	$	110,773	$	44,874	$	65,899	$	—
	Fair Value Measurements as of December 31, 2019 Using:
	Total		Level 1		Level 2		Level 3
Money market funds	$	49,948	$	49,948	$	—	$	—
Commercial paper		49,114		—		49,114		—
U.S. treasury securities		6,048		6,048		—		—
Corporate debt securities		20,143		—		20,143		—
	$	125,253	$	55,996	$	69,257	$	—