Note 10 - Stock-based Compensation - Summary of Stock Option Activity (Details) - $ / shares		12 Months Ended
		Apr. 29, 2023	Apr. 30, 2022	May 01, 2021
Statement [Line Items]
Options outstanding, beginning of year (in shares)		536,600
Options outstanding, beginning of year (in dollars per share)	[1]	$ 18.97
Granted (in shares)		0	30,000	266,500
Granted (in dollars per share)	[1]	$ 0
Exercised (in shares)		(15,300)
Exercised (in dollars per share)	[1]	$ 20.35
Cancelled (in shares)		0
Cancelled (in dollars per share)	[1]	$ 0
Options outstanding, end of year (in shares)		521,300	536,600
Options outstanding, end of year (in dollars per share)	[1]	$ 18.13	$ 18.97
Options exercisable, end of year (in shares)		336,520
Options exercisable, end of year (in dollars per share)	[1]	$ 11.90

[1] Weighted average exercise price.