Earnings Per Share (Information Necessary to Calculate Basic and Diluted Net Earnings Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ 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
Earnings Per Share [Abstract]
Net earnings	$ 64.2	$ 63.4	$ 64.4	$ 65.0	$ 58.0	$ 75.2	$ 60.1	$ 73.8	$ 257.0	$ 267.2	$ 180.3
Weighted average common shares outstanding:
Weighted average common shares – basic (in shares)									126.9	128.3	130.3
Dilutive impact of share-based awards (in shares)									1.4	2.0	1.9
Weighted average common shares – diluted (in shares)									128.3	130.3	132.2
Net earnings per share – basic (in dollars per share)	$ 0.51	$ 0.50	$ 0.51	$ 0.51	$ 0.45	$ 0.59	$ 0.47	$ 0.57	$ 2.03	$ 2.08	$ 1.38
Net earnings per share – diluted (in dollars per share)	$ 0.50	$ 0.50	$ 0.50	$ 0.51	$ 0.45	$ 0.58	$ 0.46	$ 0.56	$ 2.00	$ 2.05	$ 1.36