Segments and Disaggregated Revenue - Revenue from Contract with Customer Excluding Assessed Tax, Sam's Club (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2024	Jan. 31, 2023	Jan. 31, 2022
Revenue from External Customer [Line Items]
Net sales	$ 642,637	$ 605,881	$ 567,762
Sam's Club
Revenue from External Customer [Line Items]
Net sales	86,179	84,345	73,556
Sam's Club | E Commerce
Revenue from External Customer [Line Items]
Net sales	9,900	8,400	6,900
Grocery and consumables | Sam's Club
Revenue from External Customer [Line Items]
Net sales	56,449	53,027	46,822
Fuel, tobacco and other categories | Sam's Club
Revenue from External Customer [Line Items]
Net sales	12,854	14,636	10,751
Home and apparel | Sam's Club
Revenue from External Customer [Line Items]
Net sales	9,263	9,579	9,037
Health and wellness | Sam's Club
Revenue from External Customer [Line Items]
Net sales	5,005	4,248	3,956
Technology, office and entertainment | Sam's Club
Revenue from External Customer [Line Items]
Net sales	$ 2,608	$ 2,855	$ 2,990