Note 8 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	May 02, 2020	Apr. 27, 2019	Apr. 28, 2018	Apr. 29, 2017
Unrecognized Tax Benefits, Ending Balance	$ 1,974,000	$ 1,868,000	$ 1,733,000	$ 1,743,000
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	91,000
Changes in Income Tax if All Uncertain Tax Positions Prevail	1,600,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	267,000
Unrecognized Tax Benefits, Period Increase (Decrease), Total	$ (15,000)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	30.40%	35.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			$ (4,300,000)