Shareholders' Equity (Schedule Of Treasury Stock) (Details)	12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Balance at beginning of year	12,222,381
Net issuance upon exercise of stock options	(1,121,751)	(848,990)	(505,363)
Balance at end of year	13,245,864	12,222,381
Treasury Stock [Member]
Balance at beginning of year	12,222,381	11,295,409
Stock repurchases	1,956,648	1,651,600
Net issuance upon exercise of stock options	(862,981)	(667,991)
Issuance under compensation plans	(62,304)	(46,197)
Other activity	(7,880)	(10,440)
Balance at end of year	13,245,864	12,222,381