Note 6 - Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Prepaid Expense and Other Assets, Current [Abstract]
Interest receivable	$ 1,023	$ 880
Prepaid research and development expenses	1,041	813
Prepaid insurance	491	474
Prepaid service contracts	326	422
Other prepaid expenses	720	971
Other receivables	10	487
Other current assets	35	81
Total prepaid expenses and other current assets	$ 3,646	$ 4,128