Segment reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Nov. 01, 2013	Nov. 02, 2012	Nov. 01, 2013 segment	Nov. 02, 2012 segment
Segment reporting
Number of reportable segments			1	1
Net sales data for classes of similar products
Net sales	$ 4,381,838	$ 3,964,647	$ 13,010,222	$ 11,814,507
Consumables
Net sales data for classes of similar products
Net sales	3,362,796	3,004,247	9,859,528	8,802,350
Seasonal
Net sales data for classes of similar products
Net sales	505,793	471,541	1,610,965	1,532,772
Home products
Net sales data for classes of similar products
Net sales	276,770	257,918	807,986	772,831
Apparel
Net sales data for classes of similar products
Net sales	$ 236,479	$ 230,941	$ 731,743	$ 706,554