Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	27,413,098	27,413,098
Preferred stock, shares outstanding (in shares)	27,413,098	27,413,098
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	1,926,838	1,893,747
Common stock, shares outstanding (in shares)	1,926,838	1,893,747
Common stock, unvested or restricted share awards (in shares)	318,332	367,491