Note 10 - Net Loss Per Share (Tables)

6 Months Ended

Jun. 30, 2020

Notes Tables

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

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2020			2019			2020			2019
Weighted average common shares outstanding:
Basic		117,388			107,061			117,370			107,001
Dilutive unvested stock, convertible preferred stock, Common Stock Warrants and IPO Warrants		—			—			—			—
Diluted		117,388			107,061			117,370			107,001
Basic and diluted net loss per share attributable to common stockholders	$	(0.08	)	$	(0.07	)	$	(0.10	)	$	(0.23	)

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

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019
Unvested stock (1)		930		605		1,034		548
Convertible preferred stock		16,380		12,647		16,143		11,891
Common Stock Warrants		1,971		1,542		1,967		1,462
IPO Warrants(2)		12,082		12,082		12,082		12,082
Total potentially dilutive common shares		31,363		26,876		31,226		25,983