Note 2 - Investments and Fair Value Measurement - Fair Value of Financial Assets and Liabilities by Level Within Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Assets, fair value	$ 19,967	$ 8,499
Liabilities, fair value	2,376	1,061
Fair Value, Inputs, Level 1 [Member]
Assets, fair value	2,521	2,632
Liabilities, fair value	0	0
Fair Value, Inputs, Level 2 [Member]
Assets, fair value	17,446	5,867
Liabilities, fair value	0	0
Fair Value, Inputs, Level 3 [Member]
Assets, fair value	0	0
Liabilities, fair value	2,376	1,061
Money Market Funds [Member]
Assets, fair value	2,521	2,632
Money Market Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets, fair value	2,521	2,632
Money Market Funds [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets, fair value	0	0
Money Market Funds [Member] \| Fair Value, Inputs, Level 3 [Member]
Assets, fair value	0	0
US Government Agencies Debt Securities [Member]
Assets, fair value	17,446	5,867
US Government Agencies Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets, fair value	0	0
US Government Agencies Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets, fair value	17,446	5,867
US Government Agencies Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Assets, fair value	0	0
Warrant Liability [Member]
Liabilities, fair value	2,376	1,061
Warrant Liability [Member] \| Fair Value, Inputs, Level 1 [Member]
Liabilities, fair value	0	0
Warrant Liability [Member] \| Fair Value, Inputs, Level 2 [Member]
Liabilities, fair value	0	0
Warrant Liability [Member] \| Fair Value, Inputs, Level 3 [Member]
Liabilities, fair value	$ 2,376	$ 1,061