Stock Compensation Plan (Schedule Of Share Based Compensation Option And SARs Award Activity) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Awards, outstanding beginning balance (in shares)	2,661	2,377	2,183
Awards, granted (in shares)	651	371	377
Awards, exercised (in shares)	(74)	(67)	(46)
Awards, forfeited or expired (in shares)	(68)	(20)	(137)
Awards, outstanding ending balance (in shares)	3,170	2,661	2,377
Awards, exercisable ending balance (in shares)	2,193
Weighted-average exercise price, outstanding beginning balance (in dollars per share)	$ 32.02	$ 30.80	$ 30.49
Weighted-average exercise price, granted (in dollars per share)	$ 41.94	$ 37.40	$ 35.86
Weighted-average exercise price, exercised (in dollars per share)	$ 27.10	$ 20.06	$ 23.60
Weighted-average exercise price, forfeited or expired (in dollars per share)	$ 30.77	$ 28.59	$ 42.30
Weighted-average exercise price, outstanding ending balance (in dollars per share)	$ 34.20	$ 32.02	$ 30.80
Weighted-average exercise price, exercisable ending balance (in dollars per share)	$ 31.50
Weighted-average remaining contractual term, outstanding ending balance (in years)	6 years 4 months 2 days
Weighted-average remaining contractual term, exercisable ending balance (in years)	5 years 3 months 15 days
Aggregate intrinsic value, outstanding ending balance	$ 50,632
Aggregate intrinsic value, exercisable ending balance	$ 41,467