Segment Operating Income, Income Expense, Net and Income from Continuing Operations before Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
Apr. 30, 2017	Apr. 30, 2016
Segment Reporting Information [Line Items]
Operating income (loss):	$ 5,237	$ 5,275
Interest, net	563	561
Income from continuing operations before income taxes	4,674	4,714
Walmart U.S.
Segment Reporting Information [Line Items]
Operating income (loss):	4,269	4,232
Walmart International
Segment Reporting Information [Line Items]
Operating income (loss):	1,163	1,164
Sam's Club
Segment Reporting Information [Line Items]
Operating income (loss):	414	413
Corporate and support
Segment Reporting Information [Line Items]
Operating income (loss):	$ (609)	$ (534)

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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