Note 9 - Loss Per Share (Details Textual) - Series B Convertible Preferred Stock [Member] - shares	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Preferred Stock, Shares Outstanding (in shares)	79,246	79,246	79,246
Preferred Stock, Convertible, Shares Issuable (in shares)	16		16