Note 8 - Stock-based Compensation - Restricted Stock Activity (Details) - Restricted Stock Units (RSUs) [Member]	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Balance, unvested restricted stock units, shares (in shares) | shares	1,762,248
Balance, unvested restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.29
Granted, unvested restricted stock units, shares (in shares) | shares	106,000
Granted, unvested restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.1
Forfeited, restricted stock units, shares (in shares) | shares	(425,100)
Forfeited, restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.26
Balance, unvested restricted stock units, shares (in shares) | shares	1,443,148
Balance, unvested restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.2