Segment reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Nov. 02, 2012	Oct. 28, 2011	Nov. 02, 2012 ReportableSegments	Oct. 28, 2011 ReportableSegments
Segment reporting
Number of reportable segments			1	1
Net sales data for classes of similar products
Net sales	$ 3,964,647	$ 3,595,224	$ 11,814,507	$ 10,622,115
Consumables
Net sales data for classes of similar products
Net sales	3,004,247	2,705,765	8,802,350	7,845,905
Seasonal
Net sales data for classes of similar products
Net sales	471,541	433,931	1,532,772	1,393,557
Home products
Net sales data for classes of similar products
Net sales	257,918	236,951	772,831	706,962
Apparel
Net sales data for classes of similar products
Net sales	$ 230,941	$ 218,577	$ 706,554	$ 675,691