Shareholders' Equity (Share-Based Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2023	Jan. 31, 2022	Jan. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 1,578	$ 1,163	$ 1,169
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	927	659	742
Restricted stock and performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	444	321	277
Other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 207	$ 183	$ 150