Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 1,250	$ 637
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares, issued (in shares)	31,818,954	30,583,311
Common stock, shares, outstanding (in shares)	31,818,954	30,583,311