Segment reporting (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Feb. 02, 2018 USD ($)	Nov. 03, 2017 USD ($)	Aug. 04, 2017 USD ($)	May 05, 2017 USD ($)	Feb. 03, 2017 USD ($)	Oct. 28, 2016 USD ($)	Jul. 29, 2016 USD ($)	Apr. 29, 2016 USD ($)	Feb. 02, 2018 USD ($) segment	Feb. 03, 2017 USD ($) segment	Jan. 29, 2016 USD ($) segment
Net sales data for classes of similar products
Net sales	$ 6,129,431	$ 5,903,606	$ 5,828,305	$ 5,609,625	$ 6,009,246	$ 5,320,029	$ 5,391,891	$ 5,265,432	$ 23,470,967	$ 21,986,598	$ 20,368,562
Number of reportable segments
Number of reportable operating segments | segment									1	1	1
Consumables
Net sales data for classes of similar products
Net sales									$ 18,054,785	$ 16,798,881	$ 15,457,611
Seasonal
Net sales data for classes of similar products
Net sales									2,837,310	2,674,319	2,522,701
Home products
Net sales data for classes of similar products
Net sales									1,400,618	1,373,397	1,289,423
Apparel
Net sales data for classes of similar products
Net sales									$ 1,178,254	$ 1,140,001	$ 1,098,827