Debt (Details) (USD $)	3 Months Ended	12 Months Ended
	Oct. 25, 2014	Jul. 26, 2014
Debt Instrument [Line Items]
Debt and capital lease obligations	$ 467,359,000	$ 457,801,000
Debt premium	3,100,000	3,200,000
Senior Subordinated Notes | 7.125% Senior Subordinated Notes Due 2021
Debt Instrument [Line Items]
Debt and capital lease obligations	277,500,000	277,500,000
Debt, interest rate (in percent)	7.125%	7.125%
Debt premium	3,140,000	3,238,000
Long-term debt, fair value	290,700,000	297,600,000
Senior Loans | Credit Agreement, December 3, 2012, Maturing December 2017
Debt Instrument [Line Items]
Debt and capital lease obligations	111,719,000	114,063,000
Revolving Credit Facility
Credit facility amount	125,000,000
Debt Instrument, Interest Rate at Period End	2.15%	2.15%
Revolving Credit Facility | Credit Agreement, December 3, 2012, Maturing December 2017
Debt Instrument [Line Items]
Debt and capital lease obligations	75,000,000	63,000,000
Revolving Credit Facility
Line of credit current borrowing capacity	275,000,000
Debt Instrument, Interest Rate at Period End	2.27%	2.55%
Unutilized commitment fee (in percent)	0.35%	0.35%
Additional borrowing availability	145,700,000	162,600,000
Revolving Credit Facility | Credit Agreement, December 3, 2012, Maturing December 2017 | Standby Letters of Credit
Revolving Credit Facility
Line of credit current borrowing capacity	150,000,000
Letters of credit outstanding amount	54,300,000	49,400,000
Unutilized commitment fee (in percent)	2.00%	2.00%
Debt Premium | 7.125% Senior Subordinated Notes Due 2021
Debt Instrument [Line Items]
Debt and capital lease obligations	$ 280,600,000	$ 280,700,000