Note 10 - Net Loss Per Share (Tables)

9 Months Ended

Sep. 30, 2020

Notes Tables

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

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2020			2019			2020			2019
Weighted average common shares outstanding:
Basic		117,564			107,181			117,450			107,062
Dilutive unvested stock, convertible preferred stock, Common Stock Warrants and IPO Warrants		—			—			—			—
Diluted		117,564			107,181			117,450			107,062
Basic and diluted net loss per share attributable to common stockholders	$	(0.09	)	$	(0.06	)	$	(0.19	)	$	(0.29	)

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

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2020		2019		2020		2019
Unvested stock (1)		848		989		993		768
Convertible preferred stock		16,869		14,678		16,386		12,829
Common Stock Warrants		1,979		1,801		1,972		1,576
IPO Warrants(2)		12,082		12,082		12,082		12,082
Total potentially dilutive common shares		31,778		29,550		31,433		27,255