Segments and Disaggregated Revenue (Revenue, Walmart US) (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2022	Apr. 30, 2021
Revenue from External Customer [Line Items]
Net sales	$ 140,288	$ 137,159
Walmart U.S.
Revenue from External Customer [Line Items]
Net sales	96,904	93,167
Walmart U.S. | Grocery
Revenue from External Customer [Line Items]
Net sales	56,764	51,391
Walmart U.S. | General merchandise
Revenue from External Customer [Line Items]
Net sales	27,379	30,607
Walmart U.S. | Health and wellness
Revenue from External Customer [Line Items]
Net sales	10,894	9,970
Walmart U.S. | Other categories
Revenue from External Customer [Line Items]
Net sales	$ 1,867	$ 1,199