Short-term Borrowings and Long-term Debt (Schedule of Long-term Debt Instruments) (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2022	Apr. 30, 2021
Long-term debt due within one year
Balances as of February 1, 2022	$ 2,803
Repayments of long-term debt	(926)
Reclassifications of long-term debt	1,750
Other	(47)
Balances as of April 30, 2022	3,580	$ 3,500
Long-term debt
Balances as of February 1, 2022	34,864
Repayments of long-term debt	0
Reclassifications of long-term debt	(1,750)
Other	(940)
Balances as of April 30, 2022	32,174	40,273
Total
Balances as of February 1, 2022	37,667
Repayments of long-term debt	(926)	$ (510)
Reclassifications of long-term debt	0
Other	(987)
Balances as of April 30, 2022	$ 35,754