Condensed Consolidated Balance Sheets (Parenthetical)	Oct. 31, 2011	Jul. 31, 2011
Class A Nonvoting Common Stock
Stockholders' investment:
Common stock, shares issued	51,261,487	51,261,487
Common stock, shares outstanding	48,862,485	49,284,252
Treasury stock, shares, Class A nonvoting common stock	2,082,801	1,667,235
Class B Common Stock
Stockholders' investment:
Common stock, shares issued	3,538,628	3,538,628
Common stock, shares outstanding	3,538,628	3,538,628