Summary of Changes in Unrecognized Income Tax Benefits (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013
Income Tax Contingency [Line Items]
Beginning balance	$ 7.3	$ 6.8
Increases based on tax positions related to current year	0.8	0.9
Increases for tax positions of prior years	0.4	0.2
Decreases for tax positions of prior years	(0.8)
Decreases due to settlements with taxing authorities	(0.1)
Decreases due to lapse of the applicable statute of limitations	(0.7)	(0.6)
Adjustment due to foreign exchange rate
Ending balance	6.9	7.3
Net interest as of end of fiscal year	$ 0.6	$ 0.7