Note 10 - Stock-based Compensation - Summary of Stock Option Activity (Details) - $ / shares		12 Months Ended
		May 02, 2020	Apr. 27, 2019	Apr. 28, 2018
Options outstanding, beginning of year (in shares)		322,445
Options outstanding, beginning of year (in dollars per share)	[1]	$ 11.14
Granted (in shares)		0	9,000	500
Granted (in dollars per share)	[1]	$ 0
Exercised (in shares)		(125,100)
Exercised (in dollars per share)	[1]	$ 5.92
Cancelled (in shares)		(2,800)
Cancelled (in dollars per share)	[1]	$ 17.59
Options outstanding, end of year (in shares)		194,545	322,445
Options outstanding, end of year (in dollars per share)	[1]	$ 14.01	$ 11.14
Options exercisable, end of year (in shares)		183,145
Options exercisable, end of year (in dollars per share)	[1]	$ 13.00

[1] Weighted average exercise price.