Segment Operating Income, Income Expense, Net and Income from Continuing Operations before Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
Segment Reporting Information [Line Items]
Operating income (loss):	$ 5,119	$ 5,714	$ 16,559	$ 17,463
Interest, net	585	552	1,712	1,919
Income from continuing operations before income taxes	4,534	5,162	14,847	15,544
Walmart U.S.
Segment Reporting Information [Line Items]
Operating income (loss):	3,999	4,506	12,750	13,964
Walmart International
Segment Reporting Information [Line Items]
Operating income (loss):	1,354	1,338	4,245	3,685
Sam's Club
Segment Reporting Information [Line Items]
Operating income (loss):	396	539	1,281	1,394
Corporate and support
Segment Reporting Information [Line Items]
Operating income (loss):	$ (630)	$ (669)	$ (1,717)	$ (1,580)

Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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The net amount of operating interest income (expense).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.10)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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