Warranty (Details) - USD ($) $ in Millions |
9 Months Ended | |
|---|---|---|
Apr. 30, 2017 |
Apr. 30, 2016 |
|
| Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward] | ||
| Beginning balance | $ 11.9 | $ 8.6 |
| Accruals for warranties issued during the reporting period | 2.5 | 2.9 |
| Accruals related to pre-existing warranties (including changes in estimates) | 4.1 | 2.9 |
| Less settlements made during the period | (3.0) | (2.6) |
| Ending balance | $ 15.5 | $ 11.8 |