XML 89 R63.htm IDEA: XBRL DOCUMENT v2.4.1.9
Taxes (Details) (USD $)
 12 Months Ended
Jan. 31, 2015
Jan. 31, 2014
Jan. 31, 2013
Jan. 31, 2012
Taxes [Line Items]        
Undistributed earnings of foreign subsidiaries $ 23,300,000,000us-gaap_UndistributedEarningsOfForeignSubsidiaries $ 21,400,000,000us-gaap_UndistributedEarningsOfForeignSubsidiaries    
Operating loss and capital loss carryforwards expiring by 2033 2,900,000,000wmt_Operatinglossandcapitallosscarryforwardsexpiringbytwentytwentyfour      
Valuation allowances (1,504,000,000)us-gaap_DeferredTaxAssetsValuationAllowance (1,801,000,000)us-gaap_DeferredTaxAssetsValuationAllowance    
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount (300,000,000)us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount      
Unrecognized Tax Benefits 838,000,000us-gaap_UnrecognizedTaxBenefits 763,000,000us-gaap_UnrecognizedTaxBenefits 818,000,000us-gaap_UnrecognizedTaxBenefits 611,000,000us-gaap_UnrecognizedTaxBenefits
Unrecognized Tax Benefits that Would Impact Effective Tax Rate 763,000,000us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate 698,000,000us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate    
Interest and penalty expense (benefit) related to uncertain tax positions 18,000,000us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense (7,000,000)us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense 2,000,000us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense  
Unrecognized Tax Benefits, Interest on Income Taxes Accrued 57,000,000us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued 40,000,000us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued    
Minimum        
Taxes [Line Items]        
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit 50,000,000us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit
/ us-gaap_RangeAxis
= us-gaap_MinimumMember		      
Maximum        
Taxes [Line Items]        
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit 350,000,000us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit
/ us-gaap_RangeAxis
= us-gaap_MaximumMember		      
Operating and capital loss carryforward [Member]        
Taxes [Line Items]        
Operating loss and capital loss carryforwards 5,600,000,000us-gaap_TaxCreditCarryforwardAmount
/ us-gaap_TaxCreditCarryforwardAxis
= wmt_OperatingandcapitallosscarryforwardMember		      
Foreign tax [Member]        
Taxes [Line Items]        
Operating loss and capital loss carryforwards $ 2,000,000,000us-gaap_TaxCreditCarryforwardAmount
/ us-gaap_TaxCreditCarryforwardAxis
= wmt_ForeigntaxMember