Net Income Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012
Net Income Per Common Share [Line Items]
Consolidated net income	$ 4,215	$ 4,161	$ 8,160	$ 8,055
Less consolidated net income attributable to noncontrolling interest	(146)	(145)	(307)	(297)
Consolidated net income attributable to Walmart	$ 4,069	$ 4,016	$ 7,853	$ 7,758
Weighted-average common shares outstanding, basic	3,278	3,384	3,290	3,396
Dilutive impact of stock options and other share-based awards	13	14	15	15
Weighted-average common shares outstanding, diluted	3,291	3,398	3,305	3,411
Basic net income per common share attributable to Walmart	$ 1.24	$ 1.19	$ 2.39	$ 2.28
Diluted net income per common share attributable to Walmart	$ 1.24	$ 1.18	$ 2.38	$ 2.27