Summary of Significant Accounting Policies (Schedule of Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
Jan. 31, 2016	Jan. 31, 2015
Goodwill [Roll Forward]
Goodwill	$ 18,102	$ 19,510
Changes in currency translation and other	(1,412)	(1,418)
Acquisitions(1)	5	10
Goodwill	16,695	18,102
Walmart U.S.
Goodwill [Roll Forward]
Goodwill	461	451
Changes in currency translation and other	0	0
Acquisitions(1)	0	10
Goodwill	461	461
Walmart International
Goodwill [Roll Forward]
Goodwill	17,328	18,746
Changes in currency translation and other	(1,412)	(1,418)
Acquisitions(1)	5	0
Goodwill	15,921	17,328
Sam's Club
Goodwill [Roll Forward]
Goodwill	313	313
Changes in currency translation and other	0	0
Acquisitions(1)	0	0
Goodwill	$ 313	$ 313

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

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- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

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Amount of increase (decrease) from foreign currency translation adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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