Revenue (Disaggregation of Revenue by Geographic Region) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Disaggregation of Revenue
Net sales	$ 617.4	$ 629.7	$ 662.0	$ 672.7	$ 726.9	$ 712.8	$ 703.7	$ 701.4	$ 2,581.8	$ 2,844.9	$ 2,734.2
United States
Disaggregation of Revenue
Net sales									1,059.9	1,192.6	1,120.8
Europe, Middle East and Africa
Disaggregation of Revenue
Net sales									760.2	826.8	791.5
Asia Pacific
Disaggregation of Revenue
Net sales									553.2	597.9	599.2
Latin America
Disaggregation of Revenue
Net sales									$ 208.5	$ 227.6	$ 222.7