Revenue (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2019	Jan. 31, 2018	Jul. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract assets	$ 12.3		$ 12.3
Contract liabilities	12.6		$ 12.6		$ 10.5
Description of performance obligation timing			Generally, these contracts have terms of one year or less
Increase in net sales and cost of sales	225.4	$ 218.9	$ 463.8	$ 443.2
Calculated under Revenue Guidance in Effect before Topic 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in net sales and cost of sales	$ 3.6		$ 8.7