Accounting For Stock-Based Compensation (Summary Of Information Concerning Outstanding And Exercisable Options) (Details) - $ / shares	3 Months Ended
Oct. 31, 2015	Jul. 31, 2015
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding (in shares)	6,977,487	7,191,442
Weighted Average Remaining Contractual Life	5 years 3 months 15 days
Weighted Average Exercise Price (in usd per share)	$ 29.36
Number Exercisable (in shares)	5,264,212
Weighted Average Exercise Price (in usd per share)	$ 26.24
Range Of Exercise Prices $0.00 To $17.69 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range (in usd per share)	0
Range of Exercise Prices, upper range (in usd per share)	$ 17.69
Number Outstanding (in shares)	1,296,997
Weighted Average Remaining Contractual Life	1 year 9 months 11 days
Weighted Average Exercise Price (in usd per share)	$ 17.10
Number Exercisable (in shares)	1,296,997
Weighted Average Exercise Price (in usd per share)	$ 17.10
Range Of Exercise Prices $17.70 To $23.69 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range (in usd per share)	17.70
Range of Exercise Prices, upper range (in usd per share)	$ 23.69
Number Outstanding (in shares)	1,432,462
Weighted Average Remaining Contractual Life	3 years 3 months 4 days
Weighted Average Exercise Price (in usd per share)	$ 21.47
Number Exercisable (in shares)	1,432,462
Weighted Average Exercise Price (in usd per share)	$ 21.47
Range Of Exercise Prices $23.70 To $29.69 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range (in usd per share)	23.70
Range of Exercise Prices, upper range (in usd per share)	$ 29.69
Number Outstanding (in shares)	803,268
Weighted Average Remaining Contractual Life	5 years 1 month 2 days
Weighted Average Exercise Price (in usd per share)	$ 29.12
Number Exercisable (in shares)	803,268
Weighted Average Exercise Price (in usd per share)	$ 29.12
Range Of Exercise Prices $29.70 To $35.69 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range (in usd per share)	29.70
Range of Exercise Prices, upper range (in usd per share)	$ 35.69
Number Outstanding (in shares)	1,668,317
Weighted Average Remaining Contractual Life	6 years 5 months 9 days
Weighted Average Exercise Price (in usd per share)	$ 34.22
Number Exercisable (in shares)	1,418,936
Weighted Average Exercise Price (in usd per share)	$ 34.32
Range Of Exercise Prices $35.70 And Above [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range (in usd per share)	$ 35.70
Number Outstanding (in shares)	1,776,443
Weighted Average Remaining Contractual Life	8 years 6 months 7 days
Weighted Average Exercise Price (in usd per share)	$ 40.21
Number Exercisable (in shares)	312,549
Weighted Average Exercise Price (in usd per share)	$ 41.86

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.

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

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Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: 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

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-Publisher FASB

-Name Accounting Standards Codification

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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

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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

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

-Publisher FASB

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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

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

-Publisher FASB

-Name Accounting Standards Codification

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

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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

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-Publisher FASB

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