Note 10 - Warrants - Summary of Outstanding Common Stock Purchase Warrants (Details)	Sep. 30, 2025 $ / shares shares
Exercisable, warrants (in shares) | shares	5,901
Exercisable, warrant, weighted average exercise price (in dollars per share) | $ / shares	$ 208.75
Warrants Expiring December 2025 [Member]
Exercisable, warrants (in shares) | shares	429
Exercisable, warrant, weighted average exercise price (in dollars per share) | $ / shares	$ 1,346.4
Warrants Expiring June 2026 [Member]
Exercisable, warrants (in shares) | shares	409
Exercisable, warrant, weighted average exercise price (in dollars per share) | $ / shares	$ 1,350
Warrants Expiring April 2028 [Member]
Exercisable, warrants (in shares) | shares	5,063
Exercisable, warrant, weighted average exercise price (in dollars per share) | $ / shares	$ 20.16