Segment reporting (Details) $ in Thousands	3 Months Ended
	Apr. 29, 2016 USD ($) segment	May. 01, 2015 USD ($) segment
Net sales data for classes of similar products
Net sales	$ 5,265,432	$ 4,918,672
Number of reportable segments
Number of reportable operating segments | segment	1	1
Consumables
Net sales data for classes of similar products
Net sales	$ 4,039,197	$ 3,753,978
Seasonal
Net sales data for classes of similar products
Net sales	623,850	586,293
Home products
Net sales data for classes of similar products
Net sales	322,848	303,024
Apparel
Net sales data for classes of similar products
Net sales	$ 279,537	$ 275,377