Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Apr. 30, 2019 |
Apr. 30, 2018 |
Apr. 30, 2019 |
Apr. 30, 2018 |
|
| Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] | ||||
| Increase in other income, net | $ 4.7 | $ 4.8 | $ 7.3 | $ 7.0 |
| Decrease in operating income | $ (100.0) | (99.6) | $ (283.8) | (268.8) |
| Accounting Standards Update 2017-07 | ||||
| Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] | ||||
| Increase in other income, net | 1.5 | 4.6 | ||
| Decrease in operating income | $ 1.5 | $ 4.6 | ||