Accounting For Stock-Based Option Activity (Summary Of Information Concerning Outstanding And Exercisable Options) (Details) (USD $)	6 Months Ended
Jan. 31, 2013	Jul. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number Outstanding	7,751,084	8,056,327
Weighted Average Remaining Contractual Life (Years)	5 years 8 months 16 days
Weighted Average Exercise Price	$ 23.39
Number Exercisable	5,948,167
Weighted Average Exercise Price	$ 20.39
Range Of Exercise Prices $0.00 To $15.89 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, lower range	$ 0.00
Range of Exercise Prices, upper range	$ 15.89
Number Outstanding	1,496,222
Weighted Average Remaining Contractual Life (Years)	1 year 6 months 29 days
Weighted Average Exercise Price	$ 15.26
Number Exercisable	1,496,222
Weighted Average Exercise Price	$ 15.26
Range Of Exercise Prices $15.90 To $20.89 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, lower range	$ 15.90
Range of Exercise Prices, upper range	$ 20.89
Number Outstanding	1,985,525
Weighted Average Remaining Contractual Life (Years)	4 years 3 months 7 days
Weighted Average Exercise Price	$ 17.44
Number Exercisable	1,985,525
Weighted Average Exercise Price	$ 17.44
Range Of Exercise Prices $20.90 To $25.89 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, lower range	$ 20.90
Range of Exercise Prices, upper range	$ 25.89
Number Outstanding	1,423,462
Weighted Average Remaining Contractual Life (Years)	6 years 2 months 27 days
Weighted Average Exercise Price	$ 21.78
Number Exercisable	1,423,462
Weighted Average Exercise Price	$ 21.78
Range Of Exercise Prices $25.90 To $30.89 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, lower range	$ 25.90
Range of Exercise Prices, upper range	$ 30.89
Number Outstanding	927,849
Weighted Average Remaining Contractual Life (Years)	7 years 10 months 6 days
Weighted Average Exercise Price	$ 29.15
Number Exercisable	615,711
Weighted Average Exercise Price	$ 29.15
Range Of Exercise Prices $30.90 And Above [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, lower range	$ 30.90
Number Outstanding	1,918,026
Weighted Average Remaining Contractual Life (Years)	8 years 11 months 23 days
Weighted Average Exercise Price	$ 34.30
Number Exercisable	427,247
Weighted Average Exercise Price	$ 34.78

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(c), d(2)

-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

The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(b)

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(a)

-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

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- Definition

Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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- Definition

Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

+ References

+ Details

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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

+ References

+ Details

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- Definition

The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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