Note 5 - Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Investment securities:	$ 133,612	$ 136,629
Fair Value, Inputs, Level 3 [Member]
Investment securities:	$ 0	$ 0

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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+ Details