Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Class A nonvoting common stock
Common stock, shares Issued	51,261,487	51,261,487
Common stock, aggregate liquidation preference	$ 42,803	$ 42,803
Treasury stock, shares	3,245,561	1,667,235
Class B voting common stock
Common stock, shares Issued	3,538,628	3,538,628
Common stock, shares outstanding	3,538,628	3,538,628