Summary of Share-Based Compensation Expense Related to Employee Stock Options, Employee Stock Purchases and Non-Vested Shares (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2015	Apr. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 442	$ 513	$ 1,297	$ 1,663
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	38	110	171	343
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 404	$ 403	$ 1,126	$ 1,320