Debt (Details) (USD $)	12 Months Ended
	Apr. 27, 2013	Apr. 28, 2012	Apr. 30, 2011
Long-term debt [Abstract]
Total debt	$ 8,089,000	$ 9,760,000
Less: current portion	(513,000)	(1,829,000)
Long-term debt	7,576,000	7,931,000
Maturities of Long-term Debt [Abstract]
2014	500,000
2015	7,400,000
2016	200,000
Cash paid for interest	700,000	1,600,000	1,900,000
Maximum [Member]
Long-term debt [Abstract]
Fixed charge coverage ratio	1.05
Revolving Credit Facility [Member]
Long-term debt [Abstract]
Debt instrument, covenant description	The credit agreement includes affirmative and negative covenants that apply under certain circumstances, including a 1.05 to 1.00 fixed charge coverage ratio requirement that applies when excess availability under the line is less than 12.5% of the revolving credit commitment of $150 million.
Maximum percentage of excess availability of credit facility considered for fixed charge coverage ratio (in hundredths)	12.50%
Revolving credit, Commitment Fee Amount	150,000,000
Borrowing outstanding	0
Excess availability	143,300,000
Revolving Credit Facility [Member] | Minimum [Member]
Long-term debt [Abstract]
Fixed charge coverage ratio	1.00
Industrial Revenue Bonds [Member]
Long-term debt [Abstract]
Total debt	7,100,000	7,131,000
Interest on bonds	0.30%
Maturity date	Jun. 30, 2014
Other Debt [Member]
Long-term debt [Abstract]
Total debt	0	1,984,000
Capital Leases [Member]
Long-term debt [Abstract]
Total debt	$ 989,000	$ 645,000
Minimum interest rate (in hundredths)	7.60%
Maximum interest rate (in hundredths)	9.10%