Note 8 - Leases (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		21 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021
Operating Lease, Right-of-Use Asset, Amortization Expense	$ 21	$ 31	$ 67		$ 91
Operating Lease, Expense	$ 23	$ 34	$ 73	$ 103
Finance Lease, Weighted Average Remaining Lease Term (Year)	9 months 18 days		9 months 18 days		9 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent	7.00%		7.00%		7.00%