Note 5 - Leases - Lease Cost and Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating lease cost, net of impairment	$ 101,000	$ 86,000	$ 202,000	$ 171,000
Sublease income	(43,000)	0	(86,000)	0
Total lease cost	58,000	86,000	116,000	171,000
Cash paid for amounts included in the measurement of lease liabilities - Operating leases	$ 58,000	$ 86,000	$ 116,000	$ 171,000
Weighted-average remaining lease term - Operating leases in years (Year)	1 year 6 months 7 days	2 years 2 months 26 days	1 year 6 months 7 days	2 years 2 months 26 days
Weighted-average discount rate - Operating leases	5.75%	6.15%	5.75%	6.15%