Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands		Jun. 30, 2021	Dec. 31, 2020
Accounts receivable, allowance for doubtful account	[1]	$ 2,207	$ 4,247
Common stock, par value (in dollars per share)		$ 0.001	$ 0.001
Common stock, shares authorized (in shares)		50,000,000	50,000,000
Common stock, shares issued (in shares)		35,290,650	26,062,915
Common stock, shares outstanding (in shares)		35,290,650	26,062,915

[1] All of the VIEs' assets can be used to settle obligations of their primary beneficiary. Liabilities recognized as a result of consolidating these VIEs do not represent additional claims on the Company's general assets (Note 2).