Net Earnings Per Share (Narrative) (Details) - shares |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Apr. 30, 2017 |
Apr. 30, 2016 |
Apr. 30, 2017 |
Apr. 30, 2016 |
|
| Earnings Per Share [Abstract] | ||||
| Options excluded from the diluted net earnings per share calculation | 0 | 3,200,000 | 1,600,000 | 3,200,000 |