Fair Value Measurements using Significant Unobservable Inputs (Detail) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Balance at beginning of fiscal year	$ 15.7	$ 13.4
Actual return on plan assets
Relating to assets still held at end of fiscal year	1.5	2.2
Purchases, sales and settlements	0.6	0.9
Foreign currency exchange losses	(2.8)	(0.8)
Balance at end of fiscal year	$ 15.0	$ 15.7