Short-term Borrowings and Long-term Debt (Scheudle of Long-term Debt Instruments) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Jul. 28, 2013	Jul. 29, 2012
Debt Instrument [Line Items]
Capital Lease Obligations, Noncurrent	$ 4	$ 0
Other Long-term Debt, Noncurrent	(10)	8
Long-term Debt	3,244	2,408
Long-term Debt, Current Maturities	700	404
Long-term Debt, Excluding Current Maturities	2,544	2,004
5.00% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Dec. 03, 2012
Debt Instrument, Interest Rate, Stated Percentage	5.00%
Debt Instrument, Face Amount	0	400
4.88% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Oct. 01, 2013
Debt Instrument, Interest Rate, Stated Percentage	4.88%
Debt Instrument, Face Amount	300	300
DebtInstrumentBasisSpreadOnVariableRateMember [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Aug. 01, 2014
Debt Instrument, Basis Spread on Variable Rate	0.30%
Debt Instrument, Description of Variable Rate Basis	LIBOR plus 0.30%
Debt Instrument, Face Amount	400	0
3.38% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Aug. 15, 2014
Debt Instrument, Interest Rate, Stated Percentage	3.38%
Debt Instrument, Face Amount	300	300
3.05% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Jul. 15, 2017
Debt Instrument, Interest Rate, Stated Percentage	3.05%
Debt Instrument, Face Amount	400	400
4.50% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Feb. 15, 2019
Debt Instrument, Interest Rate, Stated Percentage	4.50%
Debt Instrument, Face Amount	300	300
4.25% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Apr. 15, 2021
Debt Instrument, Interest Rate, Stated Percentage	4.25%
Debt Instrument, Face Amount	500	500
8.88% Debentures [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	May 01, 2021
Debt Instrument, Interest Rate, Stated Percentage	8.88%
Debt Instrument, Face Amount	200	200
2.50% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Aug. 02, 2022
Debt Instrument, Interest Rate, Stated Percentage	2.50%
Debt Instrument, Face Amount	450	0
3.80% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Aug. 02, 2042
Debt Instrument, Interest Rate, Stated Percentage	3.80%
Debt Instrument, Face Amount	$ 400	$ 0

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal, through the balance sheet date and due to be paid more than one year (or one operating cycle, if longer) after the balance sheet date.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (b)

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 7, 10, 13

-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.

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-Name Accounting Standards Codification

-Topic 210

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

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- Definition

The percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

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- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16, 20

-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.

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- Definition

Interest rate stated in the contractual debt agreement.

+ References

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

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-Topic 210

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-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

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- 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

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

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-Paragraph 1

-Subparagraph (SX 210.7-03.16)

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-Name Accounting Standards Codification

-Topic 942

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-Paragraph 1

-Subparagraph (SX 210.9-03.16)

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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- Definition

Carrying value as of the balance sheet date of debt not otherwise defined (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

+ References

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