Quarterly report pursuant to Section 13 or 15(d)

Summary of significant accounting policies – Share-based compensation (Details)

v3.10.0.1
Summary of significant accounting policies – Share-based compensation (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended 9 Months Ended
Nov. 03, 2018
Oct. 28, 2017
Nov. 03, 2018
Oct. 28, 2017
Stock options        
Weighted-average assumptions to estimate fair value        
Volatility rate (as a percent)     29.00% 30.90%
Average risk-free interest rate (as a percent)     2.40% 1.60%
Average expected life     3 years 4 months 24 days 3 years 6 months
Dividend yield (as a percent)     0.00% 0.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures     163 106
Compensation expense $ 2,134 $ 2,212 $ 6,557 $ 6,589
Weighted-average grant date fair value of options granted (in dollars per share)     $ 50.10 $ 69.61
Unrecognized compensation expense 19,586   $ 19,586  
Restricted stock units        
Weighted-average assumptions to estimate fair value        
Compensation expense 3,449 2,419 9,244 $ 6,872
Unrecognized compensation expense 22,597   $ 22,597  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period     95 45
Performance-based restricted stock units        
Weighted-average assumptions to estimate fair value        
Compensation expense 1,904 $ 1,618 $ 5,083 $ 4,437
Unrecognized compensation expense $ 11,403   $ 11,403  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period     33 21