Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounts receivable, allowance for doubtful account	$ 2,236	$ 4,247
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	50,000,000
Common stock, shares issued (in shares)	35,332,677	26,062,915
Common stock, shares outstanding (in shares)	35,332,677	26,062,915