Note 6 - Leases - Lease Cost and Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating lease cost, net of impairment	$ 302,000	$ 406,000
Sublease income	(129,000)	(174,000)
Total lease cost	173,000	232,000
Cash paid for amounts included in the measurement of lease liabilities - Operating leases	$ 302,000	$ 406,000
Weighted-average remaining lease term - Operating leases in years (Year)	9 months 18 days	1 year 1 month 9 days
Weighted-average discount rate - Operating leases	4.65%	5.65%