Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Apr. 30, 2016	Jul. 31, 2015
Net of allowance for doubtful accounts (in dollars)	$ 0	$ 0
Preferred stock, Par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, Shares authorized	3,000	3,000
Preferred stock, Shares issued
Preferred stock, Shares outstanding
Treasury stock, shares	42	42
Common Stock | Class A
Common stock, Par value (in dollars per share)	$ 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, Par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, Shares authorized	40,000	40,000
Common stock, Shares issued	11,429	11,308
Common stock, Shares outstanding	11,387	11,266
Common Stock | Common stock to be issued
Common stock, Shares issued	0	60,000