Note 2 - Summary of Significant Accounting Policies - Anti-dilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities (in shares)	4,074,688	205,839
Common Stock Warrants [Member]
Antidilutive Securities (in shares)	4,009,679	135,429
Common Stock Options [ member]
Antidilutive Securities (in shares)	303	304
Preferred Stock [Member]
Antidilutive Securities (in shares)	58,080	52,289
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities (in shares)	6,626	17,817