Short-term Borrowings and Long-term Debt (Schedule of Fiscal Debt Issuances) (Details) - USD ($)	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019	Sep. 24, 2019	Apr. 23, 2019
Schedule of Fiscal 2020 and Fiscal 2019 Debt Issuances [Line Items]
Net Proceeds	$ 0	$ 5,492,000,000	$ 15,872,000,000
Unsecured debt [Member]
Schedule of Fiscal 2020 and Fiscal 2019 Debt Issuances [Line Items]
Net Proceeds	$ 0	5,492,000,000
2.850% Debt, Due 2024 [Member] | Unsecured debt [Member]
Schedule of Fiscal 2020 and Fiscal 2019 Debt Issuances [Line Items]
Principal Amount					$ 1,500,000,000
Interest Rate					2.85%
Net Proceeds		1,493,000,000
3.050% Debt, Due 2026 [Member] | Unsecured debt [Member]
Schedule of Fiscal 2020 and Fiscal 2019 Debt Issuances [Line Items]
Principal Amount					$ 1,250,000,000
Interest Rate					3.05%
Net Proceeds		1,242,000,000
3.250% Debt, Due 2029 [Member] | Unsecured debt [Member]
Schedule of Fiscal 2020 and Fiscal 2019 Debt Issuances [Line Items]
Principal Amount					$ 1,250,000,000
Interest Rate					3.25%
Net Proceeds		1,243,000,000
2.375% Debt, Due 2029 [Member] | Unsecured debt [Member]
Schedule of Fiscal 2020 and Fiscal 2019 Debt Issuances [Line Items]
Principal Amount				$ 500,000,000
Interest Rate				2.375%
Net Proceeds		497,000,000
2.950% Debt, Due 2049 [Member] | Unsecured debt [Member]
Schedule of Fiscal 2020 and Fiscal 2019 Debt Issuances [Line Items]
Principal Amount				$ 1,000,000,000
Interest Rate				2.95%
Net Proceeds		975,000,000
Various Rates, Due Various [Member] | Unsecured debt [Member]
Schedule of Fiscal 2020 and Fiscal 2019 Debt Issuances [Line Items]
Principal Amount		42,000,000
Net Proceeds		$ 42,000,000