Goodwill and Purchased Intangible Assets (Schedule of Amortization of Purchased Intangible Assets) (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Oct. 27, 2018 |
Oct. 28, 2017 |
|
| Acquired Finite-Lived Intangible Assets [Line Items] | ||
| Amortization of purchased intangible assets | $ 34 | $ 61 |
| Cost of sales | ||
| Acquired Finite-Lived Intangible Assets [Line Items] | ||
| Amortization of purchased intangible assets | 151 | 154 |
| Share-based compensation expense in operating expenses | ||
| Acquired Finite-Lived Intangible Assets [Line Items] | ||
| Amortization of purchased intangible assets | 34 | 61 |
| Total | ||
| Acquired Finite-Lived Intangible Assets [Line Items] | ||
| Amortization of purchased intangible assets | $ 185 | $ 215 |