Derivative Financial Instruments (Details) - USD ($) $ in Millions |
Jan. 31, 2021 |
Jan. 26, 2020 |
|---|---|---|
| Derivative Instruments and Hedging Activities Disclosure [Abstract] | ||
| Designated as cash flow hedges | $ 840 | $ 428 |
| Not designated for hedge accounting | $ 441 | $ 287 |