Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 854.5	$ 771.4	$ 778.7
Net other comprehensive income (loss)	7.2	48.6	(43.6)
Ending Balance	857.8	854.5	771.4
Foreign currency translation adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(58.8)	(89.3)
Other comprehensive (loss) income before reclassifications and tax	(7.3)	30.5
Tax expense	0.0	0.0
Other comprehensive (loss) income before reclassifications, net of tax	(7.3)	30.5
Reclassifications, before tax	0.0	0.0
Tax expense	0.0	0.0
Reclassifications, net of tax	0.0	0.0
Net other comprehensive income (loss)	(7.3)	30.5
Ending Balance	(66.1)	(58.8)	(89.3)
Pension benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(95.1)	(115.8)
Other comprehensive (loss) income before reclassifications and tax	11.4	24.8
Tax expense	(3.0)	(8.7)
Other comprehensive (loss) income before reclassifications, net of tax	8.4	16.1
Reclassifications, before tax	5.5	7.1
Tax expense	(1.7)	(2.5)
Reclassifications, net of tax	3.8	4.6
Net other comprehensive income (loss)	12.2	20.7
Ending Balance	(82.9)	(95.1)	(115.8)
Derivative financial instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(3.1)	(0.5)
Other comprehensive (loss) income before reclassifications and tax	3.2	(2.4)
Tax expense	(1.1)	0.8
Other comprehensive (loss) income before reclassifications, net of tax	2.1	(1.6)
Reclassifications, before tax	0.2	(1.4)
Tax expense	0.0	0.4
Reclassifications, net of tax	0.2	(1.0)
Net other comprehensive income (loss)	2.3	(2.6)
Ending Balance	(0.8)	(3.1)	(0.5)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(157.0)	(205.6)	(162.0)
Other comprehensive (loss) income before reclassifications and tax	7.3	52.9
Tax expense	(4.1)	(7.9)
Other comprehensive (loss) income before reclassifications, net of tax	3.2	45.0
Reclassifications, before tax	5.7	5.7
Tax expense	(1.7)	(2.1)
Reclassifications, net of tax	4.0	3.6
Net other comprehensive income (loss)	7.2	48.6
Ending Balance	$ (149.8)	$ (157.0)	$ (205.6)