Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Oct. 31, 2016	Jul. 31, 2016
Net of allowance for doubtful accounts	$ 0	$ 0
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	3,000	3,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Treasury stock, shares	40	40
Common Stock | Class A Common Stock
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	2,000	2,000
Common stock, shares issued	787	787
Common stock, shares outstanding	787	787
Common Stock | Class B Common Stock
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	40,000	40,000
Common stock, shares issued	11,716	11,431
Common stock, shares outstanding	11,676	11,391