Accrued Insurance Claims (Details)	Jul. 29, 2017 USD ($)	Jul. 30, 2016 USD ($) state	Jul. 25, 2015 USD ($)	Jul. 26, 2014 USD ($)
Accrued Insurance Claims [Line Items]
Number of States with State-Sponsored Insurance Fund | state		2
Aggregate stop loss coverage for automobile liability, general liability, and workers' compensation claims before adjustment		$ 84,600,000
Insurance liability, annual retained risk loss		400,000	$ 250,000	$ 250,000
Accrued Insurance		89,700,000	87,300,000
Accrued insurance claims, Noncurrent		52,835,000	51,476,000
Insurance recoveries/receivables related to accrued claims		5,700,000	9,500,000
Other Current Assets
Accrued Insurance Claims [Line Items]
Insurance recoveries/receivables related to accrued claims			600,000
Non-Current Other Assets
Accrued Insurance Claims [Line Items]
Insurance recoveries/receivables related to accrued claims			$ 8,900,000
Scenario, Forecast
Accrued Insurance Claims [Line Items]
Aggregate stop loss coverage for automobile liability, general liability, and workers' compensation claims before adjustment	$ 103,700,000
Maximum
Accrued Insurance Claims [Line Items]
Retained risk of loss, general liability and workers' compensation, maximum automobile liability		$ 1,000,000