Computation of Basic and Diluted Net (Loss) Income Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net (loss) income	$ (3,775)	$ 4,381
Weighted average number of common shares outstanding-basic	12,443	12,323
Effect of dilutive securities:
Stock options and restricted stock units		259
Weighted average number of common shares outstanding-diluted	12,443	12,582
Basic net (loss) income per share	$ (0.30)	$ 0.36
Diluted net (loss) income per share	$ (0.30)	$ 0.35