Segments and Disaggregated Revenue (Revenue from Contract with Customer Excluding Assessed Tax, Sam's Club) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2023	Jan. 31, 2022	Jan. 31, 2021
Revenue from External Customer [Line Items]
Net sales	$ 605,881	$ 567,762	$ 555,233
Sam's Club
Revenue from External Customer [Line Items]
Net sales	84,345	73,556	63,910
Sam's Club | E Commerce
Revenue from External Customer [Line Items]
Net sales	8,400	6,900	5,300
Grocery and consumables | Sam's Club
Revenue from External Customer [Line Items]
Net sales	53,027	46,822	42,148
Fuel, tobacco and other categories | Sam's Club
Revenue from External Customer [Line Items]
Net sales	14,636	10,751	7,590
Home and apparel | Sam's Club
Revenue from External Customer [Line Items]
Net sales	9,579	9,037	7,340
Health and wellness | Sam's Club
Revenue from External Customer [Line Items]
Net sales	4,248	3,956	3,792
Technology, office and entertainment | Sam's Club
Revenue from External Customer [Line Items]
Net sales	$ 2,855	$ 2,990	$ 3,040