Segments and Disaggregated Revenue (Narrative) (Details) $ in Millions	3 Months Ended
	Apr. 30, 2022 USD ($) segment	Apr. 30, 2021 USD ($)
Revenue from External Customer [Line Items]
Number of reportable segments | segment	3
Net sales	$ 140,288	$ 137,159
Walmart U.S.
Revenue from External Customer [Line Items]
Net sales	96,904	93,167
Walmart International
Revenue from External Customer [Line Items]
Net sales	23,763	27,300
Sam's Club
Revenue from External Customer [Line Items]
Net sales	19,621	16,692
eCommerceMember | Walmart U.S.
Revenue from External Customer [Line Items]
Net sales	11,400	11,300
eCommerceMember | Walmart International
Revenue from External Customer [Line Items]
Net sales	4,300	4,300
eCommerceMember | Sam's Club
Revenue from External Customer [Line Items]
Net sales	$ 1,900	$ 1,500