Commitments and Contingencies (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	May. 31, 2015	Jul. 25, 2015	Jul. 26, 2014	Jul. 27, 2013
Loss Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months		$ 17,016
Loss Contingency, Damages Sought	0.6
Operating Leases, Future Minimum Payments, Due in Two Years		11,807
Operating Leases, Future Minimum Payments, Due in Three Years		6,867
Operating Leases, Future Minimum Payments, Due in Four Years		3,724
Operating Leases, Future Minimum Payments, Due in Five Years		2,540
Operating Leases, Future Minimum Payments, Due Thereafter		6,627
Operating Leases, Future Minimum Payments Due		48,581
Operating Leases, Noncancelable Payments in Excess of One Year		18,500	$ 17,700	$ 15,300
Operating Leases, Rent Expense		20,400	20,400	$ 19,000
Credit Agreement | Credit Agreement - Revolving facility (matures April 2020) | Standby Letters of Credit
Loss Contingencies [Line Items]
Letters of credit outstanding amount		54,400	49,400
Performance Guarantee and Surety Bond
Loss Contingencies [Line Items]
Outstanding performance and other surety contract bonds		$ 294,900	$ 446,800