Share-based Awards - Black-Scholes Valuation Model Weighted-Average Assumptions (Detail)  | 
12 Months Ended | ||
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Jan. 28, 2017  | 
Jan. 30, 2016  | 
Jan. 31, 2015  | 
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| Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] | |||
| Volatility rate | 35.00% | 37.90% | 40.70% | 
| Average risk-free interest rate | 1.20% | 1.60% | 1.40% | 
| Average expected life (in years) | 3 years 6 months | 4 years 10 months 24 days | 3 years 9 months 18 days | 
| Dividend yield | 0.00% | 0.00% | 0.00% | 
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- References No definition available. 
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- Definition 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 
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Weighted average expected volatility rate of share-based compensation awards. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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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. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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