Note 7 - Stockholders' Equity - Warrants (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Balance , number of common stock warrants (in shares) | shares	2,128,429
Balance, weighted average exercise price (in dollars per share) | $ / shares	$ 6.3
Warrants for common stock sold , number of common stock warrants (in shares) | shares	1,006,488
Warrants for common stock sold, weighted average exercise price (in dollars per share) | $ / shares	$ 0.44
Balance , number of common stock warrants (in shares) | shares	3,134,917
Balance as, weighted average exercise price (in dollars per share) | $ / shares	$ 4.42