Note 2 - Supplementary Cash Flows Information - Supplementary Cash Flow Elements (Details) - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2025	Apr. 30, 2024	Apr. 30, 2023
Cash and cash equivalents (including short term investments of $33,615 and $4,136, respectively)	$ 34,077	$ 4,390	$ 7,590
State and local income tax payments	1,179	1,090	923
Restricted cash	305	305	305
Federal income tax payments	5,058	5,448	4,425
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statement of Cash Flows	$ 34,382	$ 4,695	$ 7,895

Amount of cash and cash equivalent, and cash and cash equivalent restricted to withdrawal or usage; including, but not limited to, discontinued operation. Cash includes, but is not limited to, currency on hand, demand deposit with financial institution, and account with general characteristic of demand deposit. Cash equivalent includes, but is not limited to, short-term, highly liquid investment that is both readily convertible to known amount of cash and so near maturity that it presents insignificant risk of change in value because of change in interest rate.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-8

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-24

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-4

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