Quarterly financial data (unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
	Feb. 03, 2012 week	Oct. 28, 2011 week	Jul. 29, 2011 week	Apr. 29, 2011 week	Jan. 28, 2011 week	Oct. 29, 2010 week	Jul. 30, 2010 week	Apr. 30, 2010 week	Feb. 03, 2012 Q	Jan. 28, 2011 Q	Jan. 29, 2010 Q
Selected unaudited quarterly financial data
Number of weeks in a quarter	14	13	13	13	13	13	13	13
Number of quarters in a year									4	4	4
Net sales	$ 4,185,073,000	$ 3,595,224,000	$ 3,575,194,000	$ 3,451,697,000	$ 3,486,104,000	$ 3,223,427,000	$ 3,214,155,000	$ 3,111,314,000	$ 14,807,188,000	$ 13,035,000,000	$ 11,796,380,000
Gross profit	1,346,369,000	1,115,802,000	1,148,342,000	1,087,397,000	1,130,153,000	1,010,668,000	1,035,979,000	999,756,000	4,697,910,000	4,176,556,000	3,689,871,000
Operating profit	508,240,000	310,917,000	350,029,000	321,618,000	408,251,000	274,334,000	300,757,000	290,723,000	1,490,804,000	1,274,065,000	953,258,000
Net income	292,510,000	171,164,000	146,042,000	156,969,000	222,546,000	128,120,000	141,195,000	135,996,000	766,685,000	627,857,000	339,442,000
Basic earnings per share (in dollars per share)	$ 0.86	$ 0.50	$ 0.43	$ 0.46	$ 0.65	$ 0.38	$ 0.41	$ 0.40	$ 2.25	$ 1.84	$ 1.05
Diluted earnings per share (in dollars per share)	$ 0.85	$ 0.50	$ 0.42	$ 0.45	$ 0.64	$ 0.37	$ 0.41	$ 0.39	$ 2.22	$ 1.82	$ 1.04
Principal amount of notes repurchased			839,300,000	25,000,000		65,000,000	50,000,000
Loss on debt retirement			58,100,000	2,200,000		8,200,000	6,500,000		60,303,000	14,576,000	55,265,000
Loss on repurchase of senior notes, net of tax			35,400,000	1,300,000		5,000,000	4,000,000
Share-based compensation expenses	8,600,000				3,800,000			13,300,000	23,981,000	30,171,000	22,245,000
Share-based compensation expenses, net of tax	$ 5,300,000				$ 2,300,000			$ 8,100,000	$ 14,604,000	$ 18,393,000	$ 13,587,000
Effect of pretax loss on repurchase of senior notes on earnings per diluted share (in dollars per share)			$ 0.10			$ 0.01	$ 0.01
Effect of share-based compensation expenses on earnings per diluted share (in dollars per share)	$ 0.02				$ 0.01			$ 0.02
Less than
Selected unaudited quarterly financial data
Effect of pretax loss on repurchase of senior notes on earnings per diluted share (in dollars per share)				$ 0.01