Consolidated Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized (in shares)	5,000,000	5,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	50,000,000	50,000,000
Common stock, issued (in shares)	12,979,414	12,979,414
Treasury stock, shares (in shares)	1,556,875	1,556,875