Summary of significant accounting policies (Tables)
|6 Months Ended|
Jul. 30, 2016
|Accounting Policies [Abstract]|
|Black-Scholes Valuation Model Weighted-Average Assumptions||
The Company estimated the grant date fair value of stock options using a Black-Scholes valuation model using the following weighted-average assumptions for the periods indicated:
Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions.
Reference 1: http://www.xbrl.org/2003/role/presentationRef