Note 2 - Summary of Significant Accounting Policies - Components of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash and cash equivalents	$ 3,130	$ 5,362
Restricted cash included in other assets	476	484
Total cash, cash equivalents, and restricted cash in the consolidated statements of cash flows	$ 3,606	$ 5,846	$ 7,979