Fair Value - Narrative (Detail) - USD ($)	Jul. 30, 2023	Apr. 30, 2023		Jul. 31, 2022
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments (Rabbi Trust) - available for sale	$ 8,000,000	$ 8,500,000
Long-term investments (Rabbi Trust) - available for sale	7,200,000	7,100,000		$ 9,600,000
Short-term investments (Rabbi Trust) - available for sale	791,000	1,404,000	[1]
Investments (Rabbi Trust) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Accumulated unrealized gain (loss) on investments	$ 76,000	$ 19,000		$ 25,000

[1] Derived from audited consolidated financial statements.