Note 11 - Net Loss Per Share Attributable to Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

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

	Year Ended
	December 31,
	2021			2020
Weighted average common shares outstanding:
Basic		119,201			117,524
Dilutive unvested stock, convertible preferred stock, Common Stock Warrants and IPO Warrants		—			—
Diluted		119,201			117,524
Basic and diluted net loss per share attributable to common stockholders	$	(0.34	)	$	(0.24	)

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

	Year Ended
	December 31,
	2021		2020
Unvested stock (1)		1,662		916
Convertible preferred stock		30,754		16,635
Common Stock Warrants		2,207		1,976
IPO Warrants(2)		12,082		12,082
Total potentially dilutive common shares		46,705		31,609