Note 4 - Summary of Significant Accounting Policies - Maturity of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Lessee, Operating Lease, Liability, to be Paid, Year One	$ 25
Lessee, Operating Lease, Liability, to be Paid, Year Two	0
Lessee, Operating Lease, Liability, to be Paid, Year Three	0
Lessee, Operating Lease, Liability, to be Paid, Year Four	0
-thereafter	0
Total undiscounted lease payments	25
Less: imputed interest	(1)
Operating lease liabilities as of December 31, 2023	24		$ 1,880
Operating lease liabilities	24	$ 347
Operating lease liabilities-Non current	0	$ 1,535
Operating Lease, Liability	$ 24		$ 1,880