Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ / shares in Thousands, $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts receivable, allowance for doubtful accounts	$ 214	$ 131
Preferred stock, no par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	1,250,000	1,250,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	10,570,360	10,585,159
Common stock, shares outstanding (in shares)	10,570,360	10,585,159