Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounts receivable, reserves	$ 1,358	$ 1,523
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	1,250	1,250
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	90,000	90,000
Common stock, shares issued (in shares)	14,436	14,329
Common stock, shares outstanding (in shares)	14,436	14,329