Short-term Borrowings and Long-term Debt (Debt Issued) (Details) - USD ($) $ in Millions	9 Months Ended
Oct. 31, 2022	Oct. 31, 2021
Debt Instrument [Line Items]
Net Proceeds	$ 4,969	$ 6,945
Senior Unsecured Notes
Debt Instrument [Line Items]
Net Proceeds	4,969
Senior Unsecured Notes \| 3.900% Debt, Due 2025
Debt Instrument [Line Items]
Principal Amount	$ 1,750
Interest Rate	3.90%
Net Proceeds	$ 1,744
Senior Unsecured Notes \| 3.950% Debt, Due 2027
Debt Instrument [Line Items]
Principal Amount	$ 1,000
Interest Rate	3.95%
Net Proceeds	$ 994
Senior Unsecured Notes \| 4.150% Debt, Due 2032
Debt Instrument [Line Items]
Principal Amount	$ 1,250
Interest Rate	4.15%
Net Proceeds	$ 1,239
Senior Unsecured Notes \| 4.500% Debt, Due 2052
Debt Instrument [Line Items]
Principal Amount	$ 1,000
Interest Rate	4.50%
Net Proceeds	$ 992

Face (par) amount of debt instrument at time of issuance.

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