Note 2 - Fair Value of Financial Instruments - Summary of Fair Value Hierarchy for Financial Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Assets, fair value	$ 19,983
Fair Value, Recurring [Member]
Assets, fair value	19,983	$ 25,254
Fair Value, Recurring [Member] | Money Market Securities [Member]
Assets, fair value	1,848	112
Fair Value, Recurring [Member] | Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Assets, fair value	10,340	10,633
Fair Value, Recurring [Member] | US Treasury Securities [Member]
Assets, fair value	5,955	9,192
Fair Value, Recurring [Member] | Federal Agency Notes [Member]
Assets, fair value	1,840	5,317
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, fair value	1,848	112
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Securities [Member]
Assets, fair value	1,848	112
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Assets, fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]
Assets, fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Federal Agency Notes [Member]
Assets, fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, fair value	18,135	25,142
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Securities [Member]
Assets, fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Assets, fair value	10,340	10,633
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]
Assets, fair value	5,955	9,192
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Federal Agency Notes [Member]
Assets, fair value	1,840	5,317
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Money Market Securities [Member]
Assets, fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Assets, fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Treasury Securities [Member]
Assets, fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Federal Agency Notes [Member]
Assets, fair value	$ 0	$ 0