Note 10 - Stock-based Compensation - Summary of Stock Option Activity (Details) - $ / shares		12 Months Ended
		Apr. 27, 2024	Apr. 29, 2023	Apr. 30, 2022
Options outstanding, beginning of year (in shares)		521,300
Options outstanding, beginning of year, price (in dollars per share)	[1]	$ 18.13
Granted (in shares)		0	0	30,000
Granted, price (in dollars per share)	[1]	$ 0
Exercised (in shares)		(215,000)
Exercised, price (in dollars per share)	[1]	$ 6.12
Forfeited or cancelled (in shares)		(6,400)
Forfeited or cancelled, price (in dollars per share)	[1]	$ 31.49
Options outstanding, end of year (in shares)		299,900	521,300
Options outstanding, end of year, price (in dollars per share)	[1]	$ 25.48	$ 18.13
Options vested and exercisable, end of year (in shares)		164,580
Options vested and exercisable, end of year (in dollars per share)	[1]	$ 23.4

[1] Weighted average exercise price.