Accounting For Stock-Based Compensation (Summary Of Stock Option Activity) (Details) (USD $)	3 Months Ended
	Oct. 31, 2011
Accounting For Stock-Based Compensation [Abstract]
Options Outstanding at July 31, 2011	4,193,997
Options Outstanding, Granted	2,249
Options Outstanding, Exercised	(179,866)
Options Outstanding, Canceled	(4,748)
Options Outstanding at October 31, 2011	4,011,632
Weighted Average Exercise Price, Outstanding at July 31, 2011	$ 35.44
Weighted Average Exercise Price, Granted	$ 59.47
Weighted Average Exercise Price, Exercised	$ 21.69
Weighted Average Exercise Price, Canceled	$ 48.69
Weighted Average Exercise Price, Outstanding at October 31, 2011	$ 36.06