Segments and Disaggregated Revenue (Schedule of Segment Reporting Information by Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Segment Reporting Information [Line Items]
Net sales	$ 555,233	$ 519,926	$ 510,329
Operating income (loss)	22,548	20,568	21,957
Interest, net	(2,194)	(2,410)	(2,129)
Other gains and (losses)	210	1,958	(8,368)
Income before income taxes	20,564	20,116	11,460
Loss on extinguishment of debt			(8,368)
Total assets	252,496	236,495	219,295
Depreciation and amortization	11,152	10,987	10,678
Capital expenditures	10,264	10,705	10,344
Walmart U S [Member]
Segment Reporting Information [Line Items]
Net sales	369,963	341,004	331,666
Operating income (loss)	19,116	17,380	17,386
Total assets	113,490	110,353	105,114
Depreciation and amortization	6,561	6,408	6,201
Capital expenditures	6,131	6,315	6,034
Walmart International [Member]
Segment Reporting Information [Line Items]
Net sales	121,360	120,130	120,824
Operating income (loss)	3,660	3,370	4,883
Total assets	109,445	105,811	97,066
Depreciation and amortization	2,633	2,682	2,590
Capital expenditures	2,436	2,801	2,661
Sams Club [Member]
Segment Reporting Information [Line Items]
Net sales	63,910	58,792	57,839
Operating income (loss)	1,906	1,642	1,520
Total assets	13,415	13,494	12,893
Depreciation and amortization	599	605	639
Capital expenditures	488	525	450
Corporate and support [Member]
Segment Reporting Information [Line Items]
Net sales	0	0	0
Operating income (loss)	(2,134)	(1,824)	(1,832)
Total assets	16,146	6,837	4,222
Depreciation and amortization	1,359	1,292	1,248
Capital expenditures	$ 1,209	$ 1,064	$ 1,199