Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Common stock, par value (in dollars per share)	$ 0.02	$ 0.02
Common stock, shares authorized (in shares)	25,000,000	25,000,000
Common stock, shares issued (in shares)	14,597,643	14,920,117
Common stock, shares outstanding (in shares)	14,597,643	14,920,117