Note 3 - Fair Value Measurements - Assets and Liabilities which are Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Fair Value, Inputs, Level 3 [Member]
Assets, fair value	$ 0	$ 0
Fair Value, Recurring [Member]
Assets, fair value	16,083	15,475
Fair Value, Recurring [Member] | Money Market Funds [Member]
Assets, fair value	16,083	15,475
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, fair value	16,083	15,475
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Assets, fair value	16,083	15,475
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, fair value	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Assets, fair value	0	0
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 Funds [Member]
Assets, fair value	$ 0	$ 0