Segments and Disaggregated Revenue - Revenue from Contract with Customer Excluding Assessed Tax, Sam's Club (Details) - USD ($) $ in Millions	3 Months Ended
Apr. 30, 2026	Apr. 30, 2025
Revenue from External Customer [Line Items]
Net sales	$ 175,684	$ 163,981
Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	23,405	22,064
Sam's Club U.S. \| eCommerce
Revenue from External Customer [Line Items]
Net sales	4,100	3,300
Grocery \| Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	16,102	15,443
Fuel and other \| Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	3,443	2,851
General merchandise \| Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	2,649	2,536
Health and wellness \| Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	$ 1,211	$ 1,234

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