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		6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Earnings Per Share [Abstract]
Net (loss) earnings	$ (52.9)	$ 46.5	$ 8.0	$ 104.5
Weighted average common shares outstanding:
Basic (in shares)	130.6	132.9	130.7	133.2
Dilutive impact of share based awards (in shares)	0.0	1.5	2.1	1.3
Diluted (in shares)	130.6	134.4	132.8	134.5
Basic earnings (loss) per share (in usd per share)	$ (0.40)	$ 0.35	$ 0.06	$ 0.78
Diluted net earnings (loss) per share (in usd per share)	$ (0.40)	$ 0.35	$ 0.06	$ 0.78