Note 6 - Comprehensive Income - Components of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended	15 Months Ended
Jul. 31, 2024	Jul. 31, 2023	Jul. 31, 2024
Change in unrealized gains on available-for-sale fixed income securities	$ 224	$ (270)
Change in unrealized gains on available-for-sale fixed income securities	(47)	58
Change in unrealized gains on available-for-sale fixed income securities	177	(212)
Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, before Tax, Portion Attributable to Parent	224	(270)
Other comprehensive income (loss), available-for-sale securities, tax expense	(47)	58
Other Comprehensive Income (Loss), Available-for-Sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	$ 177	$ (212)	$ (212)

Amount, before tax and after reclassification adjustment, of gain (loss) in value of unsold investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), attributable to parent.

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