Segments and Disaggregated Revenue (Revenue, Sam's Club) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2023	Jul. 31, 2022	Jul. 31, 2023	Jul. 31, 2022
Revenue from External Customer [Line Items]
Net sales	$ 160,280	$ 151,381	$ 311,284	$ 291,669
Sam's Club
Revenue from External Customer [Line Items]
Net sales	21,830	21,901	42,329	41,522
Sam's Club | Grocery and consumables
Revenue from External Customer [Line Items]
Net sales	14,325	13,392	27,823	25,693
Sam's Club | Fuel, tobacco and other categories
Revenue from External Customer [Line Items]
Net sales	3,338	4,390	6,526	7,948
Sam's Club | Home and apparel
Revenue from External Customer [Line Items]
Net sales	2,428	2,492	4,507	4,607
Sam's Club | Health and wellness
Revenue from External Customer [Line Items]
Net sales	1,186	1,006	2,342	2,016
Sam's Club | Technology, office and entertainment
Revenue from External Customer [Line Items]
Net sales	$ 553	$ 621	$ 1,131	$ 1,258