Short-term Borrowings and Long-term Debt (Significant Debt Repayments) (Details) $ in Millions	6 Months Ended
	Jul. 31, 2023 USD ($)
Debt Instrument [Line Items]
Significant Repayments of Long-Term Debt	$ 4,030
2.55% Debt, Due 2023 | Unsecured Debt
Debt Instrument [Line Items]
Principal Amount	$ 1,750
Fixed Interest Rate	2.55%
Significant Repayments of Long-Term Debt	$ 1,750
3.40% Debt, Due 2023 | Unsecured Debt
Debt Instrument [Line Items]
Principal Amount	$ 2,280
Fixed Interest Rate	3.40%
Significant Repayments of Long-Term Debt	$ 2,280