Stock Option Plans (Weighted Average Assumptions For Recognized Fair Value Of Stock-Based Employee Compensation Cost) (Details)	12 Months Ended
Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	0.05%	0.31%	0.02%
Risk-free interest rate, maximum	2.30%	2.80%	1.70%
Expected volatility, minimum	18.60%	18.20%	22.50%
Expected volatility, maximum	26.70%	28.00%	29.70%
Expected dividend yield	1.60%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield		1.60%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield		1.40%
Director Original Grants Without Reloads [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	8 years	8 years	8 years
Two Thousand Ten Master Stock Incentive Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	10 years
Reload Grants [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	4 years	6 years	5 years
Non Officer Original Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	7 years	7 years	7 years

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(2)(iii)

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

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- Definition

The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

No definition available.

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- Definition

The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

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- Definition

The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

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- Definition

The minimum risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

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.

+ References

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- Definition

Expected term of share-based compensation awards, 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 S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.D.2)

-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(2)(i)

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

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section D

-Subsection 2

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