Fair Value Measurements (Notional Amounts and Fair Values of Interest Rate Swaps) (Details) - USD ($) $ in Millions	Jan. 31, 2023	Jan. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional Amount	$ 13,921	$ 15,876
Fair Value Hedging | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional Amount	8,021	8,021
Cash Flow Hedging | Cross-currency interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional Amount	5,900	7,855
Recurring | Equity investments measured using Level 2 inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	(2,112)	(1,095)
Recurring | Fair Value Hedging | Interest Rate Swap | Equity investments measured using Level 2 inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	(689)	(47)
Recurring | Cash Flow Hedging | Cross-currency interest rate swaps | Equity investments measured using Level 2 inputs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ (1,423)	$ (1,048)