Note 7 - Income Taxes - Reconciliation of Income Tax Rate (Details)	12 Months Ended
	Apr. 28, 2018	Apr. 29, 2017	Apr. 30, 2016
Statutory federal income tax rate	30.40%	35.00%	35.00%
State income taxes, net of federal benefit	2.40%	2.20%	2.20%
Domestic manufacturing deduction benefit	(2.40%)	(3.00%)	(3.00%)
Remeasurement of deferred taxes	(2.90%)
Other differences	(0.40%)	0.10%	(0.20%)
Effective income tax rate	27.10%	34.30%	34.00%