Net (Loss) Income Per Common Share (Details Textual)	3 Months Ended		6 Months Ended
	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2012	Jan. 31, 2011
Net Income Per Common Share (Textual) [Abstract]
Number of additional shares included in computation of diluted net loss per common share	0		0
Class A Nonvoting Common Stock [Member]
Net Income Per Common Share (Textual) [Abstract]
Common stock of Class A shares excluded from computations of diluted net income per share	4,365,000	4,281,000	4,788,000	3,959,000