Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ / shares in Thousands, $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accounts receivable, allowance	$ 57	$ 57
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	43,000,000	43,000,000
Common stock, shares issued (in shares)	19,022,305	18,958,018
Common stock, shares outstanding (in shares)	19,022,305	18,958,018