Note 1 - Organization and Summary of Significant Accounting Policies - Schedule of Fair Value Measurements of Investments (Details) - USD ($) |
Jul. 31, 2025 |
Apr. 30, 2025 |
|---|---|---|
| Cash equivalents | $ 33,430,000 | $ 33,615,000 |
| Equity securities | 22,126,000 | 20,879,000 |
| Available-for-sale fixed income securities | 25,362,000 | 22,435,000 |
| Investments, Fair Value Disclosure | 80,918,000 | 76,929,000 |
| Fair Value, Inputs, Level 1 [Member] | ||
| Cash equivalents | 33,430,000 | 33,615,000 |
| Equity securities | 22,126,000 | 20,879,000 |
| Available-for-sale fixed income securities | 25,362,000 | 22,435,000 |
| Investments, Fair Value Disclosure | 80,918,000 | 76,929,000 |
| Fair Value, Inputs, Level 2 [Member] | ||
| Cash equivalents | 0 | 0 |
| Equity securities | 0 | 0 |
| Available-for-sale fixed income securities | 0 | 0 |
| Investments, Fair Value Disclosure | 0 | 0 |
| Fair Value, Inputs, Level 3 [Member] | ||
| Cash equivalents | 0 | 0 |
| Equity securities | 0 | 0 |
| Available-for-sale fixed income securities | 0 | 0 |
| Investments, Fair Value Disclosure | $ 0 | $ 0 |
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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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