Short-term Borrowings and Long-term Debt (Schedule of Debt Repayments) (Details) ¥ in Millions, $ in Millions	12 Months Ended
	Jan. 31, 2022 USD ($)	Jan. 31, 2021 USD ($)	Jan. 31, 2020 USD ($)	Sep. 23, 2021 USD ($)	Jun. 23, 2021 USD ($)	Apr. 15, 2021 USD ($)	Dec. 15, 2020 USD ($)	Oct. 25, 2020 USD ($)	Jul. 28, 2020 JPY (¥)	Jul. 08, 2020 USD ($)	Jun. 23, 2020 USD ($)
Debt Instrument [Line Items]
Repayment, Current Maturities	$ 3,010
Repayment, Excluding Current Maturities	10,000
Repayments of Long-term Debt	13,010	$ 5,382	$ 1,907
Unsecured debt [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt		5,382
4.250% Debt, Due 2021 [Member]
Debt Instrument [Line Items]
Principal Amount						$ 510
Interest Rate						4.25%
Repayment, Current Maturities	510
Floating Rate Debt, Due 2021 [Member]
Debt Instrument [Line Items]
Principal Amount					$ 750
Repayment, Current Maturities	750
3.125% Debt, Due 2021 [Member]
Debt Instrument [Line Items]
Principal Amount					$ 1,750
Interest Rate					3.125%
Repayment, Current Maturities	1,750
3.400% Debt, Due 2023 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 2,750
Interest Rate				3.40%
Repayment, Excluding Current Maturities	470
6.750% Debt, Due 2023 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 152
Interest Rate				6.75%
Repayment, Excluding Current Maturities	2
2.850% Debt, Due 2024 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 1,500
Interest Rate				2.85%
Repayment, Excluding Current Maturities	510
2.650% Debt, Due 2024 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 1,000
Interest Rate				2.65%
Repayment, Excluding Current Maturities	370
3.550% Debt, Due 2025 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 1,500
Interest Rate				3.55%
Repayment, Excluding Current Maturities	625
3.050% Debt, Due 2026 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 1,250
Interest Rate				3.05%
Repayment, Excluding Current Maturities	451
5.875% Debt, Due 2027 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 483
Interest Rate				5.875%
Repayment, Excluding Current Maturities	110
3.700% Debt, Due 2028 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 2,750
Interest Rate				3.70%
Repayment, Excluding Current Maturities	1,271
3.250% Debt, Due 2029 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 1,250
Interest Rate				3.25%
Repayment, Excluding Current Maturities	517
2.375% Debt, Due 2029 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 500
Interest Rate				2.375%
Repayment, Excluding Current Maturities	181
7.550% Debt, Due 2030 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 588
Interest Rate				7.55%
Repayment, Excluding Current Maturities	119
5.250% Debt, Due 2035 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 1,968
Interest Rate				5.25%
Repayment, Excluding Current Maturities	635
6.500% Debt, Due 2037 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 1,300
Interest Rate				6.50%
Repayment, Excluding Current Maturities	262
6.200% Debt, Due 2038 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 919
Interest Rate				6.20%
Repayment, Excluding Current Maturities	116
3.950% Debt, Due 2038 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 1,500
Interest Rate				3.95%
Repayment, Excluding Current Maturities	925
5.625% Debt, Due 2040 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 751
Interest Rate				5.625%
Repayment, Excluding Current Maturities	142
4.875% Debt, Due 2040 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 378
Interest Rate				4.875%
Repayment, Excluding Current Maturities	101
5.000% Debt, Due 2040 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 519
Interest Rate				5.00%
Repayment, Excluding Current Maturities	125
5.625% Debt, Due 2041 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 918
Interest Rate				5.625%
Repayment, Excluding Current Maturities	305
4.000% Debt, Due 2043 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 709
Interest Rate				4.00%
Repayment, Excluding Current Maturities	296
4.750% Debt, Due 2043 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 269
Interest Rate				4.75%
Repayment, Excluding Current Maturities	38
4.300% Debt, Due 2044 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 502
Interest Rate				4.30%
Repayment, Excluding Current Maturities	172
3.625% Debt, Due 2047 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 1,000
Interest Rate				3.625%
Repayment, Excluding Current Maturities	566
4.050% Debt, Due 2048 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 3,000
Interest Rate				4.05%
Repayment, Excluding Current Maturities	1,317
2.950% Debt, Due 2049 [Member]
Debt Instrument [Line Items]
Principal Amount				$ 1,000
Interest Rate				2.95%
Repayment, Excluding Current Maturities	$ 371
Floating Rate Debt, Due 2020 [Member] | Unsecured debt [Member]
Debt Instrument [Line Items]
Principal Amount											$ 750
Repayments of Long-term Debt		750
2.850% Debt, Due 2020 [Member] | Unsecured debt [Member]
Debt Instrument [Line Items]
Principal Amount											$ 1,250
Interest Rate											2.85%
Repayments of Long-term Debt		1,250
3.630% Debt Due 2020 [Member] | Unsecured debt [Member]
Debt Instrument [Line Items]
Principal Amount										$ 840
Interest Rate										3.63%
Repayments of Long-term Debt		840
1.600% Debt Due 2020 [Member] | Unsecured debt [Member]
Debt Instrument [Line Items]
Principal Amount | ¥									¥ 10,000
Interest Rate									1.60%
Repayments of Long-term Debt		95
3.250% Debt Due 2020 [Member] | Unsecured debt [Member]
Debt Instrument [Line Items]
Principal Amount								$ 1,197
Interest Rate								3.25%
Repayments of Long-term Debt		1,197
1.900% Debt Due 2020 [Member] | Unsecured debt [Member]
Debt Instrument [Line Items]
Principal Amount							$ 1,250
Interest Rate							1.90%
Repayments of Long-term Debt		$ 1,250