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Assumptions Used to Estimate Fair Value of Stock Options Granted (Detail)
 3 Months Ended
May 02, 2015
May 03, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected option term 5 years [1] 5 years [1]
Expected volatility factor 47.80%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate [2] 46.90%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate [2]
Risk-free interest rate 1.40%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate [3] 1.80%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate [3]
Expected annual dividend yield 0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate 0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
[1] We have limited historical information regarding the expected option term. Accordingly, we determined the expected option term of the awards using historical data available from comparable public companies and management's expectation of exercise behavior.
[2] Stock volatility for each grant is measured using the weighted average of historical daily price changes of our competitors' common stock over the most recent period equal to the expected option term of the awards.
[3] The risk-free interest rate is determined using the rate on treasury securities with the same term as the expected life of the stock option as of the grant date.