Note 13 - Related-party Transactions (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Apr. 30, 2022	Apr. 30, 2021
Director David Hayden [Member] \| Consulting Fees [Member]
Related Party Transaction, Amounts of Transaction	$ 135	$ 135
Edgar Law Firm LLC [Member]
Related Party Transaction, Amounts of Transaction	214	129
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	484
Chief Executive Officer [Member]
Accrued Liabilities, Current, Total	482	659
Wayne Stewart [Member]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	292	353
Jeff Shinkle [Member]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	$ 247	255
Craig Stewart [Member]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party		$ 503

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

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- Definition

Amount of selling, general and administrative expenses resulting from transactions, excluding transactions that are eliminated in consolidated or combined financial statements, with related party.

+ References

No definition available.

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