Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Assumptions to Estimate Fair Value of Stock Options (Details)

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Summary of Significant Accounting Policies - Assumptions to Estimate Fair Value of Stock Options (Details) - Stock options
9 Months Ended
Oct. 28, 2017
Oct. 29, 2016
Weighted-average assumptions to estimate fair value    
Volatility rate (as a percent) 30.90% 35.00%
Average risk-free interest rate (as a percent) 1.60% 1.20%
Average expected life 3 years 6 months 3 years 6 months
Dividend yield (as a percent) 0.00% 0.00%