Segment reporting (Details) $ in Thousands	3 Months Ended
	May 04, 2018 USD ($) segment	May 05, 2017 USD ($) segment
Net sales data for classes of similar products
Net sales	$ 6,114,463	$ 5,609,625
Number of reportable segments
Number of reportable operating segments | segment	1	1
Consumables
Net sales data for classes of similar products
Net sales	$ 4,772,388	$ 4,315,513
Seasonal
Net sales data for classes of similar products
Net sales	691,031	662,638
Home products
Net sales data for classes of similar products
Net sales	354,633	333,150
Apparel
Net sales data for classes of similar products
Net sales	$ 296,411	$ 298,324