Note 4 - Fair Value Measurements - Fair Value of Financial Instruments (Details) - Money Market Funds [Member] - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Estimate of Fair Value Measurement [Member]
Cash equivalents:
Cash equivalents	$ 46,061	$ 55,485
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Cash equivalents:
Cash equivalents	46,061	55,485
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Cash equivalents:
Cash equivalents	0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Cash equivalents:
Cash equivalents	0	0
Reported Value Measurement [Member]
Cash equivalents:
Cash equivalents	$ 46,061	$ 55,485