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Schedule of Investments and Unrealized Gains/Losses (Details) - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended
--- | --- | ---
Jan. 31, 2024 | Apr. 30, 2023
Schedule of Investments [Line Items] |  |
Amortized Cost | $ 4,377 | $ 27,790
Unrealized Gains (Losses) | 41 | 158
Market Value | 4,418 | 27,948
Corporate Bonds [Member] |  |
Schedule of Investments [Line Items] |  |
Amortized Cost | 1,767 | 14,776
Unrealized Gains (Losses) | 20 | 100
Market Value | 1,787 | 14,876
Government Bonds and Notes [Member] |  |
Schedule of Investments [Line Items] |  |
Amortized Cost | 2,610 | 9,188
Unrealized Gains (Losses) | 21 | 33
Market Value | 2,631 | 9,221
Government Agency [Member] |  |
Schedule of Investments [Line Items] |  |
Amortized Cost |  | 3,826
Unrealized Gains (Losses) |  | 25
Market Value |  | $ 3,851

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