Summary of Significant Accounting Policies (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021
Property, Plant and Equipment [Line Items]
Property and equipment	$ 189,324	$ 180,571
Accumulated depreciation	(94,809)	(88,370)
Property and equipment, net	94,515	92,201
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	19,204	19,308
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 100,376	97,582
Building and Building Improvements [Member] | [Minimum]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Building and Building Improvements [Member] | [Maximum]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	40 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 60,282	56,639
Furniture and Fixtures [Member] | [Minimum]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	1 year
Furniture and Fixtures [Member] | [Maximum]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	30 years
Transportation Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 2,263	2,301
Transportation Equipment [Member] | [Minimum]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Transportation Equipment [Member] | [Maximum]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	15 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 7,199	$ 4,741