Divestitures (Details) ¥ in Millions, £ in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jan. 31, 2021 USD ($)	Oct. 31, 2020 USD ($)	Oct. 31, 2020 USD ($)	Oct. 31, 2019 USD ($)	Nov. 15, 2020 USD ($)	Nov. 15, 2020 JPY (¥)	Oct. 02, 2020 USD ($)	Oct. 02, 2020 GBP (£)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Losses and (gains) on disposal of business operations			$ 1,028	$ (1)
Asda [Member]
Discontinued Operations and Disposal Groups [Abstract]
Enterprise Value							$ 9,100
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Enterprise Value							$ 9,100
Walmart Argentina [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Losses and (gains) on disposal of business operations		$ 1,000	$ 1,000
Seiyu [Member] | Subsequent Event [Member]
Discontinued Operations and Disposal Groups [Abstract]
Enterprise Value					$ 1,700
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Enterprise Value					$ 1,700
Losses and (gains) on disposal of business operations	$ 2,000
United Kingdom, Pounds | Asda [Member]
Discontinued Operations and Disposal Groups [Abstract]
Enterprise Value | £								£ 6,800
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Enterprise Value | £								£ 6,800
Japan, Yen | Seiyu [Member] | Subsequent Event [Member]
Discontinued Operations and Disposal Groups [Abstract]
Enterprise Value | ¥						¥ 172,500
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Enterprise Value | ¥						¥ 172,500