Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Allowance for doubtful accounts	$ 207	$ 149
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	200,000,000	200,000,000
Common stock, issued (in shares)	24,908,121	24,685,604
Common stock, outstanding (in shares)	24,908,121	24,685,604