Fair Value Measurements (Carrying Value and Fair Value of Long-Term Debt, Including Current Portion) (Details) - USD ($) $ in Millions |
Apr. 30, 2024 |
Jan. 31, 2024 |
|---|---|---|
| Carrying Value | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Long-term debt, including amounts due within one year | $ 37,793 | $ 39,579 |
| Fair Value, Inputs, Level 2 | Fair Value | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Long-term debt, including amounts due within one year | $ 34,974 | $ 38,431 |