Segments and Disaggregated Revenue (Revenue, Sam's Club) (Details) - USD ($) $ in Millions	3 Months Ended
Apr. 30, 2024	Apr. 30, 2023
Revenue from External Customer [Line Items]
Net sales	$ 159,938	$ 151,004
Sam's Club
Revenue from External Customer [Line Items]
Net sales	21,435	20,499
Sam's Club \| Grocery and consumables
Revenue from External Customer [Line Items]
Net sales	14,296	13,498
Sam's Club \| Fuel, tobacco and other categories
Revenue from External Customer [Line Items]
Net sales	3,151	3,188
Sam's Club \| Home and apparel
Revenue from External Customer [Line Items]
Net sales	2,084	2,079
Sam's Club \| Health and wellness
Revenue from External Customer [Line Items]
Net sales	1,328	1,156
Sam's Club \| Technology, office and entertainment
Revenue from External Customer [Line Items]
Net sales	$ 576	$ 578

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details