Stock-Based Compensation (Summary of Information Concerning Outstanding and Exercisable Options) (Details) - $ / shares	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range
Number outstanding (in shares)	6,533,979	6,531,250	6,785,812	6,685,551
Weighted average remaining contractual life (in years)	5 years 7 months 6 days
Weighted average exercise price (in dollars per share)	$ 42.44
Number exercisable (in shares)	4,789,048
Weighted average exercise price (in dollars per share)	$ 38.63
$28.00 to $32.49
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range
Stock options, exercise price range, lower range limit (in dollars per share)	28.00
Share options, exercise price range, upper range limit (in dollars per share)	$ 32.49
Number outstanding (in shares)	956,847
Weighted average remaining contractual life (in years)	4 years 3 months 18 days
Weighted average exercise price (in dollars per share)	$ 28.43
Number exercisable (in shares)	956,847
Weighted average exercise price (in dollars per share)	$ 28.43
$32.50 to $37.49
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range
Stock options, exercise price range, lower range limit (in dollars per share)	32.50
Share options, exercise price range, upper range limit (in dollars per share)	$ 37.49
Number outstanding (in shares)	1,047,737
Weighted average remaining contractual life (in years)	2 years 1 month 6 days
Weighted average exercise price (in dollars per share)	$ 34.39
Number exercisable (in shares)	1,047,737
Weighted average exercise price (in dollars per share)	$ 34.39
$37.50 to $42.49
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range
Stock options, exercise price range, lower range limit (in dollars per share)	37.50
Share options, exercise price range, upper range limit (in dollars per share)	$ 42.49
Number outstanding (in shares)	1,225,700
Weighted average remaining contractual life (in years)	4 years 2 months 12 days
Weighted average exercise price (in dollars per share)	$ 40.30
Number exercisable (in shares)	1,225,700
Weighted average exercise price (in dollars per share)	$ 40.30
$42.50 to $47.49
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range
Stock options, exercise price range, lower range limit (in dollars per share)	42.50
Share options, exercise price range, upper range limit (in dollars per share)	$ 47.49
Number outstanding (in shares)	1,537,884
Weighted average remaining contractual life (in years)	6 years 6 months
Weighted average exercise price (in dollars per share)	$ 43.99
Number exercisable (in shares)	1,254,073
Weighted average exercise price (in dollars per share)	$ 43.75
$47.50 and above
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range
Stock options, exercise price range, lower range limit (in dollars per share)	$ 47.50
Number outstanding (in shares)	1,765,811
Weighted average remaining contractual life (in years)	8 years 8 months 12 days
Weighted average exercise price (in dollars per share)	$ 54.95
Number exercisable (in shares)	304,691
Weighted average exercise price (in dollars per share)	$ 57.52