Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies - Recent Accounting Pronouncements Not Yet Adopted (Details)

v3.8.0.1
Summary of significant accounting policies - Recent Accounting Pronouncements Not Yet Adopted (Details) - USD ($)
$ in Thousands
Feb. 04, 2018
Feb. 03, 2018
Jan. 28, 2017
Cumulative effect of adoption of ASU 2014-09      
Retained earnings   $ 1,093,453 $ 905,785
Expected | Cumulative effect of adoption | Minimum | Accounting Standards Update (ASU) 2014 09, Revenue from Contracts with Customers      
Cumulative effect of adoption of ASU 2014-09      
Retained earnings $ 15,000    
Expected | Cumulative effect of adoption | Maximum | Accounting Standards Update (ASU) 2014 09, Revenue from Contracts with Customers      
Cumulative effect of adoption of ASU 2014-09      
Retained earnings $ 20,000