Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Jun. 30, 2021	Dec. 31, 2020
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	7,500,000	7,500,000
Common stock, shares issued (in shares)	3,805,533	3,805,533
Common stock, shares outstanding (in shares)	3,375,082	3,375,760
Treasury stock, shares (in shares)	430,451	429,773