Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Statement of Comprehensive Income [Abstract]
Net earnings	$ 102.4	$ 69.9	$ (52.9)	$ 60.9	$ 68.2	$ 60.1	$ 46.5	$ 58.0	$ 180.3	$ 232.8	$ 190.8
Other comprehensive income (loss):
Foreign currency translation (loss) income									(7.3)	30.5	(18.5)
Pension liability adjustment, net of deferred taxes of $(4.7), $(11.2) and $14.4, respectively									12.2	20.7	(25.2)
Gain (loss) on hedging derivatives, net of deferred taxes of $(1.1), $1.2 and $(0.1), respectively									2.3	(2.6)	0.1
Net other comprehensive income (loss)									7.2	48.6	(43.6)
Comprehensive income									$ 187.5	$ 281.4	$ 147.2