Segment Operating Income, Income Expense, Net And Income From Continuing Operations Before Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Apr. 30, 2014	Apr. 30, 2013
Segment Reporting Information [Line Items]
Operating income	$ 6,193	$ 6,438
Interest, net	568	530
Income from continuing operations before income taxes	5,625	5,908
Walmart U.S.
Segment Reporting Information [Line Items]
Operating income	4,975	5,197
Walmart International
Segment Reporting Information [Line Items]
Operating income	1,202	1,163
Sam's Club
Segment Reporting Information [Line Items]
Operating income	479	490
Corporate and support
Segment Reporting Information [Line Items]
Operating income	$ (463)	$ (412)