Income Taxes Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Apr. 29, 2016	Apr. 24, 2015	Apr. 25, 2014
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Statutory Federal Tax Rate	35.00%	35.00%	35.00%
State income tax — net	5.10%	0.50%	1.50%
Federal tax credits	(21.10%)	(72.40%)	(17.00%)
Domestic Production Activity Deduction	(13.40%)	(29.20%)	(8.70%)
Worthless stock	0.00%	0.00%	(1.90%)
Officers life insurance	2.40%	(6.90%)	(2.60%)
Charitable Contributions	(1.90%)	(4.50%)	(1.00%)
Settlements with state taxing authorities	0.00%	0.00%	(4.00%)
State and Local Tax Reserves	(0.30%)	(5.80%)	(0.30%)
Other	(1.10%)	0.10%	(0.50%)
Provision (benefit) for income taxes	4.70%	(83.20%)	0.50%