Consolidated Balance Sheets Parenthetical (USD $)	Apr. 30, 2012	Jul. 31, 2011
Assets
Property, building and equipment, accumulated depreciation	$ 20,239,715	$ 22,972,422
Class A [Member]
Shareholders' equity
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	2,000,000	2,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	6,000,000	6,000,000
Common stock, issued (in shares)	2,685,151	2,685,151
Treasury Stock (in shares)	83,996	125,923
Class B [Member]
Shareholders' equity
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	10,000,000	10,000,000
Common stock, issued (in shares)	1,708,574	1,708,574
Treasury Stock (in shares)	64,801	64,801