Note 12 - Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2021

Notes Tables

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

	Three Months Ended June 30,						Six Months Ended June 30,
	2021			2020			2021			2020
Net loss	$	(16,116	)	$	(8,977	)	$	(32,123	)	$	(10,274	)
Shares used to compute net loss per share – basic and diluted		120,925,570			74,675,131			118,174,099			67,676,138
Net loss per share – basic and diluted	$	(0.13	)	$	(0.12	)	$	(0.27	)	$	(0.15	)

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

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Options to purchase common stock		7,733,353		2,654,144		7,286,414		2,216,462
Performance-based restricted stock units		—		411,000		—		223,566
Warrants to purchase common stock		390,010		23,522,891		686,780		28,729,806
Total potentially dilutive securities excluded from denominator of the diluted earnings per share computation		8,123,363		26,588,035		7,973,194		31,169,834