Finite-Lived Intangible Assets (Detail) - USD ($) $ in Millions |
9 Months Ended | |
|---|---|---|
Apr. 30, 2017 |
Jul. 31, 2016 |
|
| Finite-Lived Intangible Assets [Line Items] | ||
| Cost | $ 62.3 | $ 78.9 |
| Accumulated Amortization | 42.5 | 41.3 |
| Net | $ 19.8 | 37.6 |
| Developed technologies | ||
| Finite-Lived Intangible Assets [Line Items] | ||
| Weighted-Average Amortization Period | 10 years | |
| Cost | $ 17.7 | 29.9 |
| Accumulated Amortization | 13.9 | 15.1 |
| Net | $ 3.8 | 14.8 |
| Customer relationships | ||
| Finite-Lived Intangible Assets [Line Items] | ||
| Weighted-Average Amortization Period | 13 years | |
| Cost | $ 43.7 | 47.1 |
| Accumulated Amortization | 27.7 | 25.2 |
| Net | $ 16.0 | 21.9 |
| Trade names | ||
| Finite-Lived Intangible Assets [Line Items] | ||
| Weighted-Average Amortization Period | 3 years | |
| Cost | $ 0.9 | 1.9 |
| Accumulated Amortization | $ 0.9 | 1.0 |
| Net | $ 0.9 |