Related Party Transactions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Oct. 25, 2014	Oct. 26, 2013
Related Party Transactions [Abstract]
Total expense under lease agreements	$ 0.4	$ 0.6
Related party subcontractor expense	$ 0.5	$ 0.7

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Name:	us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration