Note 7 - Commitments and Contingencies - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Current lease cost	$ 13	$ 24	$ 62	$ 57
Long-term lease cost	183	256	637	768
Total operating lease cost	196	280	699	825
Amortization of right-of-use assets	3	7	16	54
Interest on lease liabilities	0	1	1	5
Total finance lease cost	$ 3	$ 8	$ 17	$ 59
Weighted-average lease term (years), operating (Year)	3 years 25 days	3 years 6 months 25 days	3 years 25 days	3 years 6 months 25 days
Weighted-average discount rate, operating	6.38%	6.09%	6.38%	6.09%
Weighted-average lease term (years), financing (Year)	1 year 11 months 26 days	2 years 4 months 9 days	1 year 11 months 26 days	2 years 4 months 9 days
Weighted-average discount rate, financing	5.59%	5.72%	5.59%	5.72%