Short-term Borrowings and Long-term Debt (Schedule of Long-term Debt Instruments) (Details) $ in Millions	3 Months Ended
	Apr. 30, 2021 USD ($)
Long-term debt due within one year
Balances as of February 1, 2021	$ 3,115
Repayments of long-term debt	(510)
Reclassifications of long-term debt	894
Other	1
Balances as of April 30, 2021	3,500
Long-term debt
Balances as of February 1, 2021	41,194
Repayments of long-term debt	0
Reclassifications of long-term debt	(894)
Other	(27)
Balances as of April 30, 2021	40,273
Total
Balances as of February 1, 2021	44,309
Repayments of long-term debt	(510)
Reclassifications of long-term debt	0
Other	(26)
Balances as of April 30, 2021	$ 43,773