Borrowings (Short-Term Debt) (Details) (USD $) In Millions, unless otherwise specified	Apr. 30, 2011	Jul. 31, 2010
Short-term debt, amount		$ 3,037
Short-term debt, weighted-average interest rate
Commercial paper	513
Short-term debt	581	3,096
Commercial Paper [Member]
Short-term debt, weighted-average interest rate	0.26%
Current Portion of Long-Term Debt [Member]
Short-term debt, amount		3,037
Short-term debt, weighted-average interest rate		3.12%
Other Notes and Borrowings [Member]
Short-term debt, amount	$ 68	$ 59
Short-term debt, weighted-average interest rate	6.34%	4.21%

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 7

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19
-Subparagraph a(3)
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 13
-Subparagraph 2
-Article 9

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of the sum of short-term debt and current maturities of long-term debt and capital lease obligations, which are due within one year (or one business cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19
-Article 5

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Total of the portions of the carrying amounts as of the balance sheet date of long-term debt, which may include notes payable, bonds payable, debentures, mortgage loans, and commercial paper, which are scheduled to be repaid within one year or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19
-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Reflects the calculation as of the balance-sheet date of the average interest rate weighted by the amount of short-term debt outstanding by type or by instrument at that time.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19
-Subparagraph b
-Article 5

+ Details

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Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant