Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jul. 31, 2017	Jul. 31, 2016
Statement Of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 752	$ 1,070
Common stock, par value	$ 0.05	$ 0.05
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	12,467,824	12,396,765
Common stock, shares outstanding	12,467,824	12,396,765