Share-Based Payments - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended	9 Months Ended
May 09, 2015	May 10, 2014	May 09, 2015	May 10, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense related to stock options and share purchase plans	$ 9.5	$ 8.3	$ 29.7	$ 29.0
Stock options exercised - Shares			311,285	194,130
Stock options exercised - Weighted average exercise price			$ 186.40	$ 177.95
Stock options granted			329,700	347,615
Weighted average grant date fair value of options granted			$ 106.26	$ 96.92
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anti-dilutive shares excluded from the computation of earnings per share	1,140	0	2,240	0

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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

-Publisher FASB

-Name Accounting Standards Codification

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

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

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- Definition

Net number of share options (or share units) granted during the period.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

+ References

No definition available.

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Number of share options (or share units) exercised during the current period.

+ References

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