Long-term Debt Schedule of Fiscal Year 2020 Debt Maturities (Details) - USD ($) $ in Millions |
3 Months Ended | ||
|---|---|---|---|
Apr. 30, 2019 |
Apr. 30, 2018 |
Feb. 01, 2019 |
|
| Schedule of Fiscal 2020 Debt Maturities [Line Items] | |||
| Repayments of long-term debt | $ 364 | $ 2,521 | |
| 4.130% Fixed Rate Debt (500 USD), Due 2019 [Member] | Unsecured Debt [Member] | |||
| Schedule of Fiscal 2020 Debt Maturities [Line Items] | |||
| Debt instrument, principal amount | $ 500 | ||
| Debt instrument, interest rate | 4.125% | ||
| Repayments of long-term debt | $ 364 | ||