Earnings per share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Aug. 03, 2012	Jul. 29, 2011	Aug. 03, 2012	Jul. 29, 2011
Net Income
Basic earnings	$ 214,140	$ 146,042	$ 427,555	$ 303,011
Diluted Earnings	$ 214,140	$ 146,042	$ 427,555	$ 303,011
Shares
Shares outstanding, basic	333,001,000	341,534,000	334,541,000	341,528,000
Effect of dilutive share-based awards	2,520,000	4,091,000	2,966,000	3,981,000
Shares outstanding, diluted	335,521,000	345,625,000	337,507,000	345,509,000
Per Share Amount
Basic earnings per share (in dollars per share)	$ 0.64	$ 0.43	$ 1.28	$ 0.89
Diluted earnings per share (in dollars per share)	$ 0.64	$ 0.42	$ 1.27	$ 0.88
Shares of common stock outstanding excluded from computation of diluted earnings per share			1,000,000	300,000