Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	480,000,000	480,000,000
Common stock, shares issued (in shares)	149,400,000	143,500,000
Common stock, shares outstanding (in shares)	149,400,000	143,500,000
Treasury Stock, Common and Preferred, Shares	999,966	991,089
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	500,000	500,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series A Convertible Preferred Stock [Member]
Temporary equity, liquidation preference (in dollars per share)	$ 1,000	$ 1,000
Temporary equity, shares issued (in shares)	85,454	82,948
Temporary equity, shares outstanding (in shares)	85,454	82,948
Series B Convertible Preferred Stock [Member]
Temporary equity, liquidation preference (in dollars per share)	$ 1,000	$ 1,000
Temporary equity, shares issued (in shares)	81,629	79,239
Temporary equity, shares outstanding (in shares)	81,629	79,239
Series C Convertible Preferred Stock [Member]
Temporary equity, liquidation preference (in dollars per share)	$ 1,000	$ 1,000
Temporary equity, shares issued (in shares)	61,156	59,366
Temporary equity, shares outstanding (in shares)	61,156	59,366