Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Jun. 30, 2018	Dec. 31, 2017
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Preferred stock, issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	7,500,000	7,500,000
Common stock, issued (in shares)	3,782,933	3,762,933
Common stock, outstanding (in shares)	3,356,962	3,336,964
Treasury stock, shares (in shares)	425,971	425,969