Employee Benefit Plans (Summary of Share-Based Awards available for Grant) (Details) - shares |
9 Months Ended | 12 Months Ended |
|---|---|---|
Apr. 27, 2019 |
Jul. 28, 2018 |
|
| Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] | ||
| Balance, beginning of period (in shares) | 245,000,000 | 272,000,000 |
| Restricted stock, stock units, and other share-based awards granted (in shares) | (41,000,000) | (70,000,000) |
| Share-based awards canceled/forfeited/expired (in shares) | 16,000,000 | 18,000,000 |
| Shares withheld for taxes and not issued (in shares) | 17,000,000 | 25,000,000 |
| Other (in shares) | 1,000,000 | |
| Balance, end of period (in shares) | 238,000,000 | 245,000,000 |