Long-Term Debt and Credit Arrangements Schedule of Net Interest Expense (Details) - USD ($)	12 Months Ended
	Apr. 28, 2017	Apr. 29, 2016	Apr. 24, 2015
Debt Instrument [Line Items]
Capitalized interest	$ (445,000)	$ (210,000)	$ (471,000)
Total Interest Expense on outstanding borrowings	10,585,000	12,977,000	11,079,000
Accretion on note receivable	(1,133,000)	(2,082,000)	(1,859,000)
Other	(236,000)	(468,000)	(571,000)
Total Interest Income	(1,369,000)	(2,550,000)	(2,430,000)
Net Interest Expense	9,216,000	10,427,000	8,649,000
Mimi's Café
Debt Instrument [Line Items]
Sale note receivable	30,000,000
Variable-rate debt
Debt Instrument [Line Items]
Interest expense: debt	7,817,000	10,925,000	10,373,000
Fixed-rate debt
Debt Instrument [Line Items]
Interest expense: debt	$ 3,213,000	$ 2,262,000	$ 1,177,000