Note 2 - Fair Value Measurements - Schedule of Fair Value Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Cash and cash equivalents	$ 10,266	$ 16,932
Fair Value, Recurring [Member]
Unrealized Gain (Loss), before Tax	5	10
Total financial assets	17,830	35,958
Assets, Fair Value Disclosure	17,835	35,968
Total financial liabilities	26	26
Fair Value, Recurring [Member] | Cash and Cash Equivalents [Member]
Assets, Fair Value Disclosure	5,823	16,377
Fair Value, Recurring [Member] | Debt Securities Available for Sale [Member]
Assets, Fair Value Disclosure	12,012	19,591
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Money Market Funds [Member]
Cash and cash equivalents	5,823	16,377
Money market funds, fair value	5,823	16,377
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Money Market Funds [Member] | Cash and Cash Equivalents [Member]
Money market funds, fair value	5,823	16,377
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Private Placement Warrants [Member]
Private placement warrant liability	0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost	9,660	2,880
Unrealized Gain (Loss), before Tax	4	1
Debt Securities, Available-for-Sale	9,664	2,881
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Corporate Bond Securities [Member] | Debt Securities Available for Sale [Member]
Debt Securities, Available-for-Sale	9,664	2,881
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Commercial Paper [Member]
Debt Securities, Available-for-Sale, Amortized Cost	945	8,809
Unrealized Gain (Loss), before Tax	0	5
Debt Securities, Available-for-Sale	945	8,814
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Commercial Paper [Member] | Debt Securities Available for Sale [Member]
Debt Securities, Available-for-Sale	945	8,814
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US Government Debt Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost	1,402	7,892
Unrealized Gain (Loss), before Tax	1	4
Debt Securities, Available-for-Sale	1,403	7,896
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | US Government Debt Securities [Member] | Debt Securities Available for Sale [Member]
Debt Securities, Available-for-Sale	1,403	7,896
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Derivative Financial Instruments, Liabilities [Member]
Derivative warrant liability	$ 26	$ 26