Net Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2015	Oct. 31, 2014
Net Income Per Common Share [Line Items]
Income from continuing operations	$ 3,414	$ 3,826	$ 10,332	$ 11,626
Income from continuing operations attributable to noncontrolling interest	(110)	(115)	(212)	(410)
Income from continuing operations attributable to Walmart	$ 3,304	$ 3,711	$ 10,120	$ 11,216
Weighted-average common shares outstanding, basic	3,210	3,229	3,221	3,231
Dilutive impact of stock options and other share-based awards	9	11	10	12
Weighted-average common shares outstanding, diluted	3,219	3,240	3,231	3,243
Basic income per common share from continuing operations attributable to Walmart	$ 1.03	$ 1.15	$ 3.14	$ 3.47
Diluted income per common share from continuing operations attributable to Walmart	$ 1.03	$ 1.15	$ 3.13	$ 3.46