Note 10 - Equity, Share-based Compensation, Warrants and Securities Offerings - Exercisable and Outstanding (Details) - $ / shares	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Weighted Average Exercise Price (in dollars per share)	$ 0.21	$ 1.76	$ 9.76
Warrants [Member]
Shares Under Warrants (in shares)	0.21
Weighted Average Exercise Price (in dollars per share)	$ 4.1
Warrants [Member] | Exercise Range One [Member]
Shares Under Warrants (in shares)	0.18
Weighted Average Exercise Price (in dollars per share)	$ 4.9
Warrants [Member] | Exercise Price Range Two [Member]
Shares Under Warrants (in shares)	0.2
Weighted Average Exercise Price (in dollars per share)	$ 1.8
Warrants [Member] | Exercise Price Range Three [Member]
Shares Under Warrants (in shares)	1.88
Weighted Average Exercise Price (in dollars per share)	$ 3.8