Note 9 - Net Loss Per Share of Common Stock (Tables)

6 Months Ended

Jun. 30, 2021

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2021			2020			2021			2020
Net loss	$	(7,105	)	$	(5,041	)	$	(15,109	)	$	(15,837	)
Basic and diluted net loss per share	$	(0.35	)	$	(0.32	)	$	(0.78	)	$	(1.02	)
Weighted-average shares used to compute basic and diluted net loss per share		20,414			15,902			19,247			15,457

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Six Months Ended
	June 30,
	2021		2020
Options to purchase common stock		2,298,237		2,080,075
Restricted stock units		—		2,844