Retirement-Related Benefits (Schedule of Contribution Expense Related to Defined Contribution Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2023	Jan. 31, 2022	Jan. 31, 2021
Contribution expense from retirement plans [Line Items]
Total contribution expense for defined contribution plans	$ 1,565	$ 1,480	$ 1,490
U.S.
Contribution expense from retirement plans [Line Items]
Total contribution expense for defined contribution plans	1,491	1,441	1,290
International
Contribution expense from retirement plans [Line Items]
Total contribution expense for defined contribution plans	$ 74	$ 39	$ 200