Stockholders' Equity - Additional Information (Detail) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011
Class of Stock [Line Items]
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares outstanding	0	0
Common stock, shares authorized	250,000	250,000
Common stock, voting rights	One vote for each share held