Accounting For Stock-Based Compensation (Summary Of Information Concerning Outstanding And Exercisable Options) (Details) (USD $)
6 Months Ended
Jan. 31, 2015
Jul. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]    
Number Outstanding 7,573,315 7,197,882
Weighted Average Remaining Contractual Life (Years) 5 years 10 months 24 days  
Weighted Average Exercise Price $ 29.08  
Number Exercisable 5,756,328  
Weighted Average Exercise Price $ 25.95  
Range Of Exercise Prices $0.00 To $17.69 [Member]    
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]    
Range of Exercise Prices, lower range $ 0.00  
Range of Exercise Prices, upper range $ 17.69  
Number Outstanding 1,571,174  
Weighted Average Remaining Contractual Life (Years) 2 years 3 months 15 days  
Weighted Average Exercise Price $ 17.01  
Number Exercisable 1,571,174  
Weighted Average Exercise Price $ 17.01  
Range Of Exercise Prices $17.70 To $23.69 [Member]    
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]    
Range of Exercise Prices, lower range $ 17.70  
Range of Exercise Prices, upper range $ 23.69  
Number Outstanding 1,488,345  
Weighted Average Remaining Contractual Life (Years) 4 years 7 days  
Weighted Average Exercise Price $ 21.44  
Number Exercisable 1,488,345  
Weighted Average Exercise Price $ 21.44  
Range Of Exercise Prices $23.70 To $29.69 [Member]    
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]    
Range of Exercise Prices, lower range $ 23.70  
Range of Exercise Prices, upper range $ 29.69  
Number Outstanding 844,768  
Weighted Average Remaining Contractual Life (Years) 5 years 10 months 2 days  
Weighted Average Exercise Price $ 29.12  
Number Exercisable 844,768  
Weighted Average Exercise Price $ 29.12  
Range Of Exercise Prices $29.70 To $35.69 [Member]    
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]    
Range of Exercise Prices, lower range $ 29.70  
Range of Exercise Prices, upper range $ 35.69  
Number Outstanding 1,778,353  
Weighted Average Remaining Contractual Life (Years) 7 years 2 months 12 days  
Weighted Average Exercise Price $ 34.23  
Number Exercisable 1,506,618  
Weighted Average Exercise Price $ 34.32  
Range Of Exercise Prices $35.70 And Above [Member]    
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]    
Range of Exercise Prices, lower range $ 35.70  
Number Outstanding 1,890,675  
Weighted Average Remaining Contractual Life (Years) 9 years 2 months 5 days  
Weighted Average Exercise Price $ 40.26  
Number Exercisable 345,423  
Weighted Average Exercise Price $ 41.78