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Summary of significant accounting policies - Additional Information (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified |
3 Months Ended | 9 Months Ended | ||
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Oct. 27, 2012
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Oct. 29, 2011
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Oct. 27, 2012
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Oct. 29, 2011
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Number of shares granted in stock option | 213 | 595 | ||
| Weighted average fair value of stock option | $ 45.84 | $ 34.74 | ||
| Stock compensation expenses | $ 3,375 | $ 3,027 | $ 9,721 | $ 8,223 |
| Unrecognized compensation expense related to unvested stock awards | $ 32,340 | $ 32,340 | ||
| X | ||||||||||
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- Definition
As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Net number of share options (or share units) granted during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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