Segments and Disaggregated Revenue - Revenue from Contract with Customer Excluding Assessed Tax, Sam's Club (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2023
Revenue from External Customer [Line Items]
Net sales	$ 674,538	$ 642,637	$ 605,881
Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	90,238	86,179	84,345
Sam's Club U.S. | E Commerce
Revenue from External Customer [Line Items]
Net sales	12,100	9,900	8,400
Grocery | Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	59,976	56,455	53,055
Fuel and other | Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	12,924	13,678	15,385
General merchandise | Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	11,249	11,041	11,669
Health and wellness | Sam's Club U.S.
Revenue from External Customer [Line Items]
Net sales	$ 6,089	$ 5,005	$ 4,236