Share-Based Payments - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	8 Months Ended
May 04, 2019	May 05, 2018	May 04, 2019	May 05, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value of options granted			$ 208.37	$ 129.12
Stock options granted			172,750	284,335
Stock options exercised - Shares			408,657	243,370
Stock options exercised - Weighted average exercise price			$ 412.75	$ 281.72
share-based compensation expense	$ 10.0	$ 5.8	$ 31.5	$ 29.6
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value of options granted			$ 773.57
Restricted stock units granted			10,507
Non vested restricted stock unit award	$ 6.2		$ 6.2
Estimated weighted average period			3 years 4 months 24 days
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	4,177	861,595	149,648	850,421

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.

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-Name Accounting Standards Codification
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-SubTopic 10
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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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

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Amount of capitalized and expensed compensation cost from equity-based compensation arrangements.

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Intrinsic value of equity-based compensation awards not vested. Excludes stock and unit options.

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

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