Stockholders' Equity Stock-Option Activity and Related Share-Based Compensation Expense (Details) shares in Thousands	3 Months Ended
	Oct. 31, 2015 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | shares	8,713
Options granted, number of shares (in shares) | shares	3
Options exercised, number of shares (in shares) | shares	(357)
Options canceled or expired, number of shares (in shares) | shares	(210)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | shares	8,149
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price per share, Beginning Balance (in dollars per share)	$ 69.13
Options granted, weighted average exercise price per share (in dollars per share)	88.30
Options exercised, weighted average exercise price per share (in dollars per share)	53.17
Options canceled or expired, weighted average exercise price per share (in dollars per share)	70.78
Weighted average exercise price per share, Beginning Balance (in dollars per share)	$ 69.79
Exercisable (in shares) | shares	4,367
Exercisable, Weighted average exercise price per share (in dollars per share)	$ 52.27