Consolidated Balance Sheets (Parentheticals) - $ / shares	Apr. 30, 2022	Apr. 30, 2021
Statement of Financial Position [Abstract]
Preferred stock, no par value (in usd per share)	$ 0	$ 0
Preferred stock, shares issued (in shares)	0	0
Common stock, no par value (in usd per share)	$ 0	$ 0
Common stock, shares issued (in shares)	37,111,667	36,949,878
Common stock, shares outstanding (in shares)	37,111,667	36,949,878

Face amount per share of no-par value common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

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- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

Face amount per share of no-par value preferred stock nonredeemable or redeemable solely at the option of the issuer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (a)
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Section S99
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Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

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