Note 8 - Stock-based Compensation - Restricted Stock Activity (Details) - Restricted Stock Units (RSUs) [Member]	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Beginning balance, unvested restricted stock units, shares (in shares) | shares	767,048
Beginning balance, unvested restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.32
Granted, unvested restricted stock units, shares (in shares) | shares	965,200
Granted, unvested restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.26
Vested, restricted stock units, shares (in shares) | shares	(45,000)
Vested, restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.37
Ending balance, unvested restricted stock units, shares (in shares) | shares	1,687,248
Ending balance, unvested restricted stock units, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.29