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