Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Jun. 30, 2024	Dec. 31, 2023
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	62,000	62,000
Preferred stock, shares outstanding (in shares)	62,000	62,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	53,564,680	53,390,082
Common stock, shares outstanding (in shares)	53,506,748	53,332,150
Series A Redeemable Convertible Preferred Stock [Member]
Temporary equity, shares authorized (in shares)	165,000	165,000
Temporary equity, shares issued (in shares)	62,000	62,000
Temporary equity, shares outstanding (in shares)	62,000	62,000
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares outstanding (in shares)	62,000