Note 7 - Fair Value Measurements - Fair Value Hierarchy for Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Corporate, municipal debt and treasury securities	$ 5,642	$ 5,410
Total assets	25,631
Corporate Debt Securities [Member]
Corporate, municipal debt and treasury securities	5,642
Money Market Funds [Member]
Money market accounts	19,989
Fair Value, Inputs, Level 1 [Member]
Total assets	25,631
Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member]
Corporate, municipal debt and treasury securities	5,642
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Money market accounts	19,989
Fair Value, Inputs, Level 2 [Member]
Total assets	0
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Corporate, municipal debt and treasury securities	0
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Money market accounts	0
Fair Value, Inputs, Level 3 [Member]
Total assets	0
Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]
Corporate, municipal debt and treasury securities	0
Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]
Money market accounts	$ 0