Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
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Data Type:	num:percentItemType
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Percentage employer matches of the employee's percentage contribution matched.

No definition available.

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Percentage of employer's matching contributions to a defined contribution plan that vests in a given year.

No definition available.

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Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
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Data Type:	num:percentItemType
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Amount of increase (decrease) in obligation for pension benefits. Includes, but is not limited to, defined benefit or defined contribution plans. Excludes other postretirement benefits.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

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[Line Items] for Contribution expense from retirement plans [Table]

No definition available.

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Data Type:	xbrli:stringItemType
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Disposal Group, Including Discontinued Operation, Other Comprehensive Income (Loss), Defined Benefit Plan, Expected Reclassification Adjustment from AOCI, after Tax

No definition available.

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Data Type:	xbrli:monetaryItemType
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Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=wmt_AsdaMember
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Balance Type:
Period Type:

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: