Fair Value Measurements (Details 1) (Fair Value, Measurements, Recurring [Member], USD $) In Millions, unless otherwise specified	Jul. 31, 2013	Jul. 31, 2012
Cash equivalents:
Cash equivalents	$ 917	$ 333
Available-for-sale securities:
Investments	893	600
Cash equivalents in cash and cash equivalents [Member]
Cash equivalents:
Cash equivalents	857	219
Cash equivalents in funds held for customers [Member]
Cash equivalents:
Cash equivalents	60	114
In investments [Member]
Available-for-sale securities:
Investments	652	351
In funds held for customers [Member]
Available-for-sale securities:
Investments	175	175
In long-term investments [Member]
Available-for-sale securities:
Investments	66	74
Level 1 [Member]
Cash equivalents:
Cash equivalents	917	333
Available-for-sale securities:
Investments	33	33
Level 1 [Member] \| Cash equivalents in cash and cash equivalents [Member]
Cash equivalents:
Cash equivalents	857	219
Level 1 [Member] \| Cash equivalents in funds held for customers [Member]
Cash equivalents:
Cash equivalents	60	114
Level 1 [Member] \| In investments [Member]
Available-for-sale securities:
Investments	0	0
Level 1 [Member] \| In funds held for customers [Member]
Available-for-sale securities:
Investments	0	0
Level 1 [Member] \| In long-term investments [Member]
Available-for-sale securities:
Investments	33	33
Level 2 [Member]
Cash equivalents:
Cash equivalents	0	0
Available-for-sale securities:
Investments	827	526
Level 2 [Member] \| Cash equivalents in cash and cash equivalents [Member]
Cash equivalents:
Cash equivalents	0	0
Level 2 [Member] \| Cash equivalents in funds held for customers [Member]
Cash equivalents:
Cash equivalents	0	0
Level 2 [Member] \| In investments [Member]
Available-for-sale securities:
Investments	652	351
Level 2 [Member] \| In funds held for customers [Member]
Available-for-sale securities:
Investments	175	175
Level 2 [Member] \| In long-term investments [Member]
Available-for-sale securities:
Investments	0	0
Level 3 [Member]
Cash equivalents:
Cash equivalents	0	0
Available-for-sale securities:
Investments	33	41
Level 3 [Member] \| Cash equivalents in cash and cash equivalents [Member]
Cash equivalents:
Cash equivalents	0	0
Level 3 [Member] \| Cash equivalents in funds held for customers [Member]
Cash equivalents:
Cash equivalents	0	0
Level 3 [Member] \| In investments [Member]
Available-for-sale securities:
Investments	0	0
Level 3 [Member] \| In funds held for customers [Member]
Available-for-sale securities:
Investments	0	0
Level 3 [Member] \| In long-term investments [Member]
Available-for-sale securities:
Investments	$ 33	$ 41

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Company may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months.

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