Note 1 - Organization and Summary of Significant Accounting Policies - Fair Value Hierarchy for Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Corporate, municipal debt and treasury securities	$ 5,410	$ 5,230
Total assets	18,874	28,278
Corporate Debt Securities [Member]
Corporate, municipal debt and treasury securities	5,410	5,230
Fair Value, Inputs, Level 1 [Member]
Corporate, municipal debt and treasury securities		5,230
Total assets	18,874	28,278
Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member]
Corporate, municipal debt and treasury securities	5,410
Money Market Funds [Member]
Money market accounts	13,464	23,048
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Money market accounts	$ 13,464	$ 23,048