Note 3 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Contract with Customer, Performance Obligation Satisfied in Previous Period			$ 0	$ 0
Research and Development Expense, Total		$ 56	$ 89	124	$ 163
Operating Lease, Right-of-Use Asset	[1]	2,038		2,038		$ 2,019
Operating Lease, Liability, Total		2,139		2,139
Other Current Assets [Member]
Operating Lease, Right-of-Use Asset		2,040		2,040
Operating Lease, Liability, Total		$ 2,140		$ 2,140

[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).