Note 1 - Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	May 02, 2020	Apr. 27, 2019	Apr. 28, 2018
Balance at beginning of year	$ 516	$ 452	$ 468
Net charge to expense	893	87	34
Net charge-off	(59)	(23)	(50)
Balance at end of year	$ 1,350	$ 516	$ 452