Note 5 - Fair Value Measurements - Assets Categorized on Basis of Various Levels (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Sep. 30, 2025
Assets, fair value	$ 30,919	$ 66,751
Money Market Funds [Member]
Assets, fair value	30,906	66,739
Mutual Fund Investment [Member]
Assets, fair value	13	12
Cash and Cash Equivalents [Member]
Assets, fair value	30,906	66,739
Marketable Securities [Member]
Assets, fair value	13	12
Fair Value, Inputs, Level 1 [Member]
Assets, fair value	30,919	66,751
Fair Value, Inputs, Level 1 [Member] \| Money Market Funds [Member]
Assets, fair value	30,906	66,739
Fair Value, Inputs, Level 1 [Member] \| Mutual Fund Investment [Member]
Assets, fair value	13	12
Fair Value, Inputs, Level 1 [Member] \| Cash and Cash Equivalents [Member]
Assets, fair value	30,906	66,739
Fair Value, Inputs, Level 1 [Member] \| Marketable Securities [Member]
Assets, fair value	13	12
Fair Value, Inputs, Level 2 [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 2 [Member] \| Money Market Funds [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 2 [Member] \| Mutual Fund Investment [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 2 [Member] \| Cash and Cash Equivalents [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 2 [Member] \| Marketable Securities [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 3 [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 3 [Member] \| Money Market Funds [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 3 [Member] \| Mutual Fund Investment [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 3 [Member] \| Cash and Cash Equivalents [Member]
Assets, fair value	0	0
Fair Value, Inputs, Level 3 [Member] \| Marketable Securities [Member]
Assets, fair value	$ 0	$ 0