Consolidated Statements Of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member]	Capital in excess of par value [Member]	Retained earnings [Member]	Retained earnings [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated other comprehensive income (loss) [Member]	Accumulated other comprehensive income (loss) [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Total Walmart shareholders' equity [Member]	Total Walmart shareholders' equity [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Noncontrolling interest [Member]	Noncontrolling interest [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]
Beginning balances (in shares) at Jan. 31, 2018			2,952
Beginning balances at Jan. 31, 2018	$ 80,822	$ 924	$ 295	$ 2,648	$ 85,107	$ 2,361	$ (10,181)	$ (1,436)	$ 77,869	$ 925	$ 2,953	$ (1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income	7,179				6,670				6,670		509
Other comprehensive income (loss), net of income taxes	(113)						75		75		(188)
Cash dividends declared	(6,102)				(6,102)				(6,102)
Purchase of Company stock (in shares)			(80)
Purchase of Company stock	(7,487)		$ (8)	(245)	(7,234)				(7,487)
Cash dividend declared to noncontrolling interest	(488)										(488)
Noncontrolling interest of acquired entity	4,345										4,345
Other (in shares)			6
Other	554		$ 1	562	(17)				546		8
Ending balances (in shares) at Jan. 31, 2019			2,878
Ending balances at Jan. 31, 2019	79,634	$ (300)	$ 288	2,965	80,785	$ (266)	(11,542)		72,496	$ (266)	7,138	$ (34)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income	15,201				14,881				14,881		320
Other comprehensive income (loss), net of income taxes	(1,235)						(1,263)		(1,263)		28
Cash dividends declared	(6,048)				(6,048)				(6,048)
Purchase of Company stock (in shares)			(53)
Purchase of Company stock	(5,639)		$ (5)	(199)	(5,435)				(5,639)
Cash dividend declared to noncontrolling interest	(475)										(475)
Other (in shares)			7
Other	414		$ 1	481	26				508		(94)
Ending balances (in shares) at Jan. 31, 2020			2,832
Ending balances at Jan. 31, 2020	81,552		$ 284	3,247	83,943		(12,805)		74,669		6,883
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income	13,706				13,510				13,510		196
Other comprehensive income (loss), net of income taxes	826						1,039		1,039		(213)
Cash dividends declared	(6,116)				(6,116)				(6,116)
Purchase of Company stock (in shares)			(20)
Purchase of Company stock	(2,658)		$ (2)	(97)	(2,559)				(2,658)
Cash dividend declared to noncontrolling interest	(365)										(365)
Other (in shares)			9
Other	586			496	(15)				481		105
Ending balances (in shares) at Jan. 31, 2021			2,821
Ending balances at Jan. 31, 2021	$ 87,531		$ 282	$ 3,646	$ 88,763		$ (11,766)		$ 80,925		$ 6,606