Earnings per share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Nov. 01, 2013	Oct. 31, 2014	Nov. 01, 2013
Net Income
Basic earnings	$ 236,316	$ 237,385	$ 709,974	$ 702,943
Diluted Earnings	$ 236,316	$ 237,385	$ 709,974	$ 702,943
Shares
Shares outstanding, basic	303,080,000	321,711,000	305,142,000	324,485,000
Effect of dilutive share-based awards	1,028,000	832,000	955,000	953,000
Shares outstanding, diluted	304,108,000	322,543,000	306,097,000	325,438,000
Per Share Amount
Basic earnings per share (in dollars per share)	$ 0.78	$ 0.74	$ 2.33	$ 2.17
Diluted earnings per share (in dollars per share)	$ 0.78	$ 0.74	$ 2.32	$ 2.16
Share-based awards outstanding excluded from computation of diluted earnings per share	1,000,000	1,100,000