Debt - Narrative (Details)		3 Months Ended
	Jan. 02, 2014 USD ($)	Jul. 24, 2015 USD ($)	Jul. 25, 2014 USD ($)	Apr. 24, 2015 USD ($)	Jul. 23, 2014 USD ($)
Line of Credit Facility [Line Items]
Total borrowings		$ 491,057,000		$ 451,085,000
Revolving credit facility, maximum borrowing capacity	$ 750,000,000
Revolving credit facility	750,000,000
Line of credit facility, amount outstanding	50,000,000	$ 487,668,000
Change in interest rate		1.00%
Accordion option	$ 1,050,000,000
Credit facility unused capacity commitment fee percentage low end of range	0.15%
Credit facility unused capacity commitment fee percentage high end of range	0.25%
Financing costs	$ 2,064,000	$ 1,705,000
Unamortized debt financing cost	$ 760,000
Effective interest rate		2.21%	1.66%
Letters of credit outstanding, amount		$ 12,419,000
Impact of change in effective interest rate		$ 4,944,000
LIBOR
Line of Credit Facility [Line Items]
Credit facility variable rate low end	1.00%
Credit facility variable rate high end	2.75%
Debt instrument, basis spread on variable rate	1.00%
Base Rate
Line of Credit Facility [Line Items]
Credit facility variable rate low end	0.00%
Credit facility variable rate high end	1.75%
Federal Funds Rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate	0.50%
First Amendment to the Credit Agreement | Credit Agreement borrowings
Line of Credit Facility [Line Items]
Unamortized debt financing cost					$ 1,279,000
Coverage ratio requirement		3.00
Leverage ratio requirement		4.50
Current coverage ratio		12.42
Current leverage ratio		3.22
Credit agreement, additional indebtedness					300,000,000
Credit agreement, sale leaseback capacity					100,000,000
Credit agreement, additional capacity, mortgage indebtedness					$ 50,000,000
Credit Agreement borrowings
Line of Credit Facility [Line Items]
Total borrowings		$ 487,668,000		447,599,000
Credit Agreement borrowings | Standby Letters of Credit
Line of Credit Facility [Line Items]
Line of credit facility, amount outstanding		12,118,000
R&D Loan
Line of Credit Facility [Line Items]
Total borrowings		2,529,000		2,631,000
Loans payable			$ 3,000,000
Interest-free loan
Line of Credit Facility [Line Items]
Total borrowings		860,000		$ 855,000
Loans payable			$ 1,000,000
Debt instrument, term			10 years
OHIO | R&D Loan
Line of Credit Facility [Line Items]
Total borrowings		$ 2,529,000