Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands |
3 Months Ended | 9 Months Ended | ||
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Oct. 31, 2015 |
Nov. 01, 2014 |
Oct. 31, 2015 |
Nov. 01, 2014 |
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| Employee Stock Option [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Number of shares granted | 295 | 362 | ||
| Weighted-average fair value of stock option | $ 57.40 | $ 32.22 | ||
| Compensation expenses | $ 1,743 | $ 2,386 | $ 5,682 | $ 6,990 |
| Unrecognized compensation expense | 25,543 | $ 25,543 | ||
| Restricted Stock [Member] | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Number of shares granted | 77 | 70 | ||
| Compensation expenses | 1,805 | $ 1,447 | $ 5,444 | $ 4,446 |
| Unrecognized compensation expense | $ 12,880 | $ 12,880 | ||
| X | ||||||||||
- Definition 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
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- Definition Unrecognized cost of unvested share-based compensation awards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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. No definition available.
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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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- 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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