Basis of Presentation and Accounting Policies (Details) $ in Thousands	3 Months Ended	12 Months Ended
Oct. 29, 2016 USD ($) segment	Oct. 24, 2015	Jul. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment	1
Prepaid Expense and Other Assets	$ 18,000		$ 17,700
Debt Issuance Costs, Net	5,900		6,400
Insurance recoveries/receivables related to accrued claims	5,600		5,700
Restricted cash	5,500		5,000
Investments and other noncurrent assets	$ 4,000		$ 4,000
Fiscal period duration	364 days		371 days
Non-Current Other Assets
Segment Reporting Information [Line Items]
Insurance recoveries/receivables related to accrued claims			$ 5,700
Revenue Recognized Using Cost To Cost Percentage of Completion Method \| Maximum
Segment Reporting Information [Line Items]
Contract revenues	5.00%	10.00%
Stock Options
Segment Reporting Information [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years		4 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years		10 years
Performance RSUs
Segment Reporting Information [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years		3 years
Supplemental Shares
Segment Reporting Information [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years		3 years
RSUs
Segment Reporting Information [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years		4 years

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
-Section 45
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The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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