2.2.0.25falsefalse40801 - Disclosure - Note 8. Fair Value Measurements (The Carrying Value and Fair Value of our Debt) (Details)truefalseIn Millionsfalse1falsefalseUSDfalsefalse1/31/2011
USD ($)
USD ($) / shares
$As_Of_1_31_2011http://www.sec.gov/CIK0000104169instant2011-01-31T00:00:000001-01-01T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit16Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit15Standardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$2falsefalseUSDfalsefalse1/31/2010
USD ($)
USD ($) / shares
$As_Of_1_31_2010http://www.sec.gov/CIK0000104169instant2010-01-31T00:00:000001-01-01T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit1Standardhttp://www.xbrl.org/2003/instancesharesxbrli0Unit16Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit15Standardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$2true0wmt_FairValueMeasurementAbstractwmtfalsenadurationfair value measurement [Abstract]falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringfair value measurement [Abstract]falsefalse3false0us-gaap_LongTermDebtus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse4534700000045347falsetruefalsefalsefalse2truefalsefalse3728100000037281falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIncluding current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date. May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 7
Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9
Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20, 22
-Article 5
falsefalse4false0us-gaap_DebtInstrumentFairValueus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse4701200000047012falsetruefalsefalsefalse2truefalsefalse3905500000039055falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryEstimated fair value of the debt instrument at the balance-sheet date.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 10
falsefalse23Note 8. Fair Value Measurements (The Carrying Value and Fair Value of our Debt) (Details) (USD $)MillionsUnKnownUnKnownUnKnownfalsetrue
