Basis of Presentation and Accounting Policies (Details) - segment	9 Months Ended	12 Months Ended
Apr. 29, 2017	Jul. 30, 2016
Segment Reporting Information [Line Items]
Number of reportable segments	1
Fiscal period duration	364 days	371 days

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

No definition available.

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration