CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
CONSOLIDATED BALANCE SHEETS
Allowance for doubtful accounts	$ 176	$ 141
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	28,385,299	28,345,525
Common stock, shares outstanding (in shares)	27,124,292	27,075,962
Treasury stock, common shares (in shares)	1,261,007	1,269,563