Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	25,000,000	25,000,000
Common stock, shares issued (in shares)	8,154,474	7,840,124
Common stock, shares outstanding (in shares)	8,010,837	7,696,487
Treasury Stock (in shares)	143,637	143,637
Series A Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0