Other Expense, Net - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2014	Jan. 31, 2013	Oct. 31, 2013 PocketSonics	Jan. 31, 2014 PocketSonics
Component Of Other Expense Income Nonoperating [Line Items]
Loss from pre-acquisition equity interest					$ 0.5	$ 0.5
Foreign exchange losses	$ 0.4	$ 0.5	$ 0.5	$ 1.5