Net Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
Net Income Per Common Share [Line Items]
Income from continuing operations	$ 3,635	$ 4,089	$ 6,918	$ 7,800
Income from continuing operations attributable to noncontrolling interest	(160)	(166)	(102)	(295)
Income from continuing operations attributable to Walmart	$ 3,475	$ 3,923	$ 6,816	$ 7,505
Weighted-average common shares outstanding, basic	3,221	3,230	3,226	3,231
Dilutive impact of stock options and other share-based awards	10	11	11	13
Weighted-average common shares outstanding, diluted	3,231	3,241	3,237	3,244
Basic income per common share from continuing operations attributable to Walmart	$ 1.08	$ 1.22	$ 2.11	$ 2.32
Diluted income per common share from continuing operations attributable to Walmart	$ 1.08	$ 1.21	$ 2.11	$ 2.31