Stock Based Compensation (Summary Of Information Concerning Outstanding And Exercisable Options) (Details) - $ / shares	3 Months Ended
Oct. 31, 2017	Jul. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding (in shares)	7,304,945	6,685,551
Weighted Average Remaining Contractual Life (Years)	6 years
Weighted Average Exercise Price of Outstanding Options (in usd per share)	$ 34.25
Number Exercisable (in shares)	4,723,701
Weighted Average Exercise Price of Exercisable Options (in usd per share)	$ 31.29
$ 0.00 to $22.69
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)	$ 22.69
Number Outstanding (in shares)	1,129,408
Weighted Average Remaining Contractual Life (Years)	1 year 8 months 16 days
Weighted Average Exercise Price of Outstanding Options (in usd per share)	$ 19.67
Number Exercisable (in shares)	1,129,408
Weighted Average Exercise Price of Exercisable Options (in usd per share)	$ 19.67
$22.70 to $28.69
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range (in usd per share)	22.7
Range of Exercise Prices, upper range (in usd per share)	$ 28.69
Number Outstanding (in shares)	906,002
Weighted Average Remaining Contractual Life (Years)	7 years 10 months 13 days
Weighted Average Exercise Price of Outstanding Options (in usd per share)	$ 27.90
Number Exercisable (in shares)	315,426
Weighted Average Exercise Price of Exercisable Options (in usd per share)	$ 27.58
$28.70 to $34.69
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range (in usd per share)	28.7
Range of Exercise Prices, upper range (in usd per share)	$ 34.69
Number Outstanding (in shares)	1,444,975
Weighted Average Remaining Contractual Life (Years)	4 years 1 month 24 days
Weighted Average Exercise Price of Outstanding Options (in usd per share)	$ 31.61
Number Exercisable (in shares)	1,427,244
Weighted Average Exercise Price of Exercisable Options (in usd per share)	$ 31.61
$34.70 to $40.69
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range (in usd per share)	34.7
Range of Exercise Prices, upper range (in usd per share)	$ 40.69
Number Outstanding (in shares)	1,437,465
Weighted Average Remaining Contractual Life (Years)	5 years 10 months 21 days
Weighted Average Exercise Price of Outstanding Options (in usd per share)	$ 37.03
Number Exercisable (in shares)	1,153,628
Weighted Average Exercise Price of Exercisable Options (in usd per share)	$ 36.66
$40.70 and above
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range (in usd per share)	$ 40.7
Number Outstanding (in shares)	2,387,095
Weighted Average Remaining Contractual Life (Years)	8 years 5 months 27 days
Weighted Average Exercise Price of Outstanding Options (in usd per share)	$ 43.47
Number Exercisable (in shares)	697,995
Weighted Average Exercise Price of Exercisable Options (in usd per share)	$ 42.25

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=96867065&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=96867065&loc=d3e5070-113901

Reference 2: 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=96867065&loc=d3e5070-113901

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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
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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.

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