Income Taxes - Summary of Valuation Allowances Against Net Deferred Income Tax Assets (Detail) - USD ($) $ in Thousands	Jul. 30, 2023	Apr. 30, 2023	Jul. 31, 2022
Valuation Allowance [Line Items]
Valuation allowance	$ 19,576	$ 18,675	$ 13,336
U.S. Capital Loss Carry Forwards [Member]
Valuation Allowance [Line Items]
Valuation allowance	2,330	2,330	2,330
U.S. Federal and State [Member] \| Deferred Income Tax Assets [Member]
Valuation Allowance [Line Items]
Valuation allowance	$ 17,246	$ 16,345	$ 11,006

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-2

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