Segments and Disaggregated Revenue (Revenue, Sam's Club) (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Revenue from External Customer [Line Items]
Net sales	$ 151,004	$ 140,288
Sam's Club
Revenue from External Customer [Line Items]
Net sales	20,499	19,621
Sam's Club | Grocery and consumables
Revenue from External Customer [Line Items]
Net sales	13,498	12,301
Sam's Club | Fuel, tobacco and other categories
Revenue from External Customer [Line Items]
Net sales	3,188	3,558
Sam's Club | Home and apparel
Revenue from External Customer [Line Items]
Net sales	2,079	2,115
Sam's Club | Health and wellness
Revenue from External Customer [Line Items]
Net sales	1,156	1,010
Sam's Club | Technology, office and entertainment
Revenue from External Customer [Line Items]
Net sales	$ 578	$ 637