Fair Value of Hedging Portfolio Related to Interest Rate Contract (Detail) (Interest Rate Contract, Accrued Expenses, USD $) In Millions, unless otherwise specified	Jan. 28, 2012	Jul. 30, 2011
Interest Rate Contract \| Accrued Expenses
Derivatives, Fair Value [Line Items]
Fair Value of derivative liabilities	$ 2.0	$ 3.3

Fair value of all liability derivatives designated as cash flow hedging instruments.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5624163-113959

Name:	us-gaap_CashFlowHedgeDerivativeInstrumentLiabilitiesAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant