Segments and Disaggregated Revenue - Revenue from Contract with Customer Excluding Assessed Tax, Sam's Club (Details) - USD ($) $ in Millions	12 Months Ended
Jan. 31, 2026	Jan. 31, 2025	Jan. 31, 2024
Revenue from External Customer [Line Items]
Net sales	$ 706,413	$ 674,538	$ 642,637
Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	93,015	90,238	86,179
Sam's Club U.S. \| E Commerce
Revenue from External Customer [Line Items]
Net sales	15,000	12,100	9,900
Grocery \| Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	64,706	61,253	57,565
Fuel and other \| Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	11,570	12,960	13,707
General merchandise \| Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	11,549	11,215	10,947
Health and wellness \| Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	$ 5,190	$ 4,810	$ 3,960

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