Segment reporting (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 03, 2018 USD ($) segment	Aug. 04, 2017 USD ($) segment	Aug. 03, 2018 USD ($) segment	Aug. 04, 2017 USD ($) segment
Net sales data for classes of similar products
Net sales	$ 6,443,309	$ 5,828,305	$ 12,557,772	$ 11,437,930
Number of reportable segments
Number of reportable operating segments | segment	1	1	1	1
Consumables
Net sales data for classes of similar products
Net sales	$ 4,988,063	$ 4,484,359	$ 9,760,451	$ 8,799,872
Seasonal
Net sales data for classes of similar products
Net sales	792,513	717,993	1,483,544	1,380,631
Home products
Net sales data for classes of similar products
Net sales	345,161	327,648	699,794	660,798
Apparel
Net sales data for classes of similar products
Net sales	$ 317,572	$ 298,305	$ 613,983	$ 596,629