Net Income Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Oct. 31, 2011		Oct. 31, 2010		Oct. 31, 2011		Oct. 31, 2010
Net Income Per Common Share [Abstract]
Antidilutive stock options and share-based awards excluded from computation of diluted net income per common share					9		11
Income from continuing operations	$ 3,501		$ 3,590		$ 11,016		$ 10,781
Less consolidated net income attributable to noncontrolling interest	(157)	[1]	(154)	[1]	(444)	[2]	(448)	[2]
Income from continuing operations attributable to Walmart	$ 3,344		$ 3,436		$ 10,572		$ 10,333
Weighted-average common shares outstanding, basic	3,445		3,617		3,473		3,692
Dilutive impact of stock options and other share-based awards	13		14		14		14
Weighted-average common shares outstanding, diluted	3,458		3,631		3,487		3,706
Basic	$ 0.97		$ 0.95		$ 3.04		$ 2.80
Diluted	$ 0.97		$ 0.95		$ 3.03		$ 2.79

[1] Includes $11 million and $4 million for the three months ended October 31, 2011 and 2010, respectively, related to the redeemable noncontrolling interest.

[2] Includes $40 million and $6 million for the nine months ended October 31, 2011 and 2010, respectively, related to the redeemable noncontrolling interest.