Change in Benefit Obligation (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Current service cost	$ 1.1	$ 1.4	$ 1.1
Interest cost	0.6	0.6	0.6
Plan participants contributions	0.2	0.3
Benefit payments	(0.9)	(0.6)
Transfers from other plans	(0.1)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Balance at beginning period	14.5	15.5
Current service cost	1.1	1.4
Foreign currency exchange (gain) loss	(0.9)	(0.4)
Interest cost	0.7	0.6
Net actuarial loss (gain)	3.3	(2.3)
Plan participants contributions	0.2	0.3
Benefit payments	(0.9)	(0.6)
Transfers from other plans	0.1
Balance at end of year	$ 18.1	$ 14.5