Valuation and Qualifying Accounts (Details) (USD $) In Millions	12 Months Ended
Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Allowance for Doubtful Accounts, Current [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowances and reserves, beginning balance	$ 22	$ 16	$ 16
Valuation allowances and reserves, additions charged to expense/revenue	18	23	14
Valuation allowances and reserves, deductions	(20)	(17)	(14)
Valuation allowances and reserves, ending balance	20	22	16
Allowance for Product Returns [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowances and reserves, beginning balance	20	22	28
Valuation allowances and reserves, additions charged to expense/revenue	94	101	107
Valuation allowances and reserves, deductions	(94)	(103)	(113)
Valuation allowances and reserves, ending balance	20	20	22
Reserve For Rebates [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation allowances and reserves, beginning balance	11	30	13
Valuation allowances and reserves, additions charged to expense/revenue	90	84	114
Valuation allowances and reserves, deductions	(90)	(103)	(97)
Valuation allowances and reserves, ending balance	$ 11	$ 11	$ 30

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 09
-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e24092-122690

+ Details

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- Definition

+ References

+ Details

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- Definition

Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

+ References

+ Details

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