Change in Benefit Obligation (Detail) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Current service cost	$ 0.6	$ 1.3	$ 1.1
Interest cost	0.7	0.7	0.6
Plan participant contributions	0.1	0.2
Benefit payments	(1.5)	(0.4)
Transfer from other plans	(0.2)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Balance at beginning of year	17.0	18.1
Current service cost	0.6	1.3
Foreign currency exchange loss (gain)	0.1	(3.2)
Interest cost	0.7	0.7
Net actuarial loss	2.1	0.3
Plan participant contributions	0.1	0.2
Benefit payments	(1.5)	(0.4)
Transfer from other plans	0.2
Balance at end of year	$ 19.3	$ 17.0	$ 18.1