Segment reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 28, 2011	Oct. 29, 2010	Oct. 28, 2011 segment	Oct. 29, 2010 segment
Segment reporting
Number of reportable segments			1	1
Segment reporting
Net sales	$ 3,595,224	$ 3,223,427	$ 10,622,115	$ 9,548,896
Consumables
Segment reporting
Net sales	2,705,765	2,378,667	7,845,905	6,907,541
Seasonal
Segment reporting
Net sales	433,931	401,544	1,393,557	1,302,780
Home products
Segment reporting
Net sales	236,951	223,026	706,962	670,352
Apparel
Segment reporting
Net sales	$ 218,577	$ 220,190	$ 675,691	$ 668,223