Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	4,000,000	4,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	40,000,000	40,000,000
Common stock, shares issued (in shares)	5,887,899	5,887,899
Common stock, shares outstanding (in shares)	5,732,441	5,731,442
Treasury stock, shares (in shares)	155,458	156,457