Property, Plant and Equipment - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			12 Months Ended
	Jul. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Property, Plant and Equipment [Line Items]
Net cash proceeds from land and buildings and improvements	$ 7,352			$ 8,699	$ 361	$ 629
Gain on the sale of land and buildings and improvements	1,888			1,897	47	209
Non-cash impairment charge		$ 710	$ 2,000	$ 710	$ 2,000