Stockholders' Equity - Share-Based Awards Available for Grant (Details) - shares	12 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares available for Grant, Beginning (in shares)	22,791,000	25,164,000	8,990,000
Additional shares authorized (in shares)			23,110,000
Restricted stock units granted (in shares)	5,639,000	6,504,000	9,160,000
Options granted (in shares)	(487,000)	(455,000)	(1,786,000)
Share-based awards canceled/forfeited/expired (in shares)	4,393,000	4,586,000	4,010,000
Shares available for Grant, Ending (in shares)	21,058,000	22,791,000	25,164,000
Pool shares reduced for each share granted (in shares)	2.3
Pool shares increased for each share forfeited (in shares)	2.3