Note 8 - Share-based Compensation - Summary of Non-vested RSUs (Details)	9 Months Ended
	Sep. 30, 2022 $ / shares shares
RSUs granted, weighted average grant date fair value per share (in dollars per share) | $ / shares	$ 1.49
RSUs released, weighted average grant date fair value per share (in dollars per share) | $ / shares	2.72
RSUs forfeited, weighted average grant date fair value per share (in dollars per share) | $ / shares	1.49
Balance, weighted average grant date fair value per share (in dollars per share) | $ / shares	$ 3.81
Restricted Stock Units (RSUs) [Member]
Balance, shares (in shares) | shares	200,271
Balance, weighted average grant date fair value per share (in dollars per share) | $ / shares	$ 4.13
RSUs granted, shares (in shares) | shares	269,204
RSUs released, shares (in shares) | shares	(328,958)
RSUs forfeited, shares (in shares) | shares	(87,718)
Balance, shares (in shares) | shares	52,799