Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Senior revolving credit facility, interest payable current	$ 731	$ 892
Senior revolving credit facility, interest payable noncurrent	$ 249	$ 485
Preferred stock, par value (in dollars per share)	$ 0.005	$ 0.005
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.005	$ 0.005
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	11,439,633	6,307,868
Treasury stock, shares (in shares)	6,907	6,907
Common stock, shares outstanding (in shares)	11,432,726	6,300,961