Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Statement of Comprehensive Income [Abstract]
Pension and postretirement liability adjustment, deferred taxes	$ (11.2)	$ 14.4	$ (0.2)
(Loss) gain on hedging derivatives, deferred taxes	$ 1.2	$ (0.1)	$ 0.4