Short-term Borrowings and Long-term Debt (Details)	12 Months Ended
Jan. 31, 2019 USD ($) Financial_institution	Jan. 31, 2018 USD ($)	Jan. 31, 2017 USD ($)
Debt Instrument [Line Items]
Short-term borrowings	$ 5,225,000,000	$ 5,257,000,000
Short-term debt, weighted average interest rate, at point in time	2.70%	1.50%
Number of financial institutions committing to lend funds under lines of credit \| Financial_institution	22
Available	$ 15,000,000,000	$ 12,500,000,000
Line of Credit Facility, Capacity Available for Trade Purchases	400,000,000	400,000,000
Secured long-term debt, noncurrent	8,000,000	10,000,000
Carrying value of property collateralizing long term debt	82,000,000	101,000,000
Payment for Debt Extinguishment or Debt Prepayment Cost	0	3,059,000,000	$ 0
Loss on extinguishment of debt	0	(3,136,000,000)	$ 0
Unsecured debt
Debt Instrument [Line Items]
Payment for Debt Extinguishment or Debt Prepayment Cost		11,272,000,000
Walmart International
Debt Instrument [Line Items]
Available	3,000,000,000	4,000,000,000
Line of Credit, Current	$ 200,000,000	0.0
Minimum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	10.00%
Line of credit facility, commitment fee percentage	1.50%
Maximum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	75.00%
Line of credit facility, commitment fee percentage	4.00%
Put Option [Member]
Debt Instrument [Line Items]
Long-term debt, gross		500,000,000
Fronted and Syndicated Lines of Credit [Member]
Debt Instrument [Line Items]
Available	$ 1,800,000,000	1,800,000,000
Line of Credit, Current	1,600,000,000	1,500,000,000
Five Year Facility [Member]
Debt Instrument [Line Items]
Available	$ 5,000,000,000	$ 5,000,000,000

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

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- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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- Definition

The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

+ References

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- Definition

Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets.

+ References

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- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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- Definition

Weighted average interest rate of short-term debt outstanding calculated at point in time.

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- Definition

Carrying value of property collateralizing long-term debt

+ References

No definition available.

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- Definition

Number of financial institutions committing to lend funds under lines of credit

+ References

No definition available.

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