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Marketable Securities (Details) - Schedule of Realized Gain (Loss) on Investments - USD ($) $ in Thousands | 12 Months Ended
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Apr. 30, 2020 | Apr. 30, 2019
Schedule of Realized Gain (Loss) on Investments [Abstract] |  |
Proceeds | $ 3,539 | $ 1,812
Gross realized gains | 0 | 3
Gross realized losses | $ (1) | $ 0

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- Definition This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
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- Definition This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
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