Fair Value - Additional Information (Detail) (USD $)	Jan. 26, 2013	Jul. 28, 2012
Disclosure Fair Value Additional Information [Abstract]
Equity Method Investments	$ 239,000,000	$ 249,000,000
Loan Receivables And Financed Service Contracts And Others Carrying Value	2,000,000,000	1,900,000,000
Long-term Debt, Fair Value	18,300,000,000	18,800,000,000
Long-term Debt	$ 16,300,000,000	$ 16,300,000,000

This item represents the aggregate carrying amount of all cost-method investments as reported on or included in the balance sheet. The original cost of the investments may differ from the aggregate carrying amount disclosed due to various adjustments such as: (i) dividends received in excess of earnings after the date of investment that are considered a return of investment and therefore recorded as reductions to cost of the investment, or (ii) a series of operating losses of an investee or other factors which may indicate that a decrease in value of the investment has occurred which is other than temporary and accordingly such decrease in value has been recognized.

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

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-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 03-1

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

+ Details

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References+ Details