CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' DEFICIT - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
Stockholders' equity, beginning balance at Jul. 31, 2020	$ (274,977)	$ 5	$ 2,245,180	$ 2,030	$ (2,522,192)
Stockholders' equity, beginning balance (in shares) at Jul. 31, 2020		201,949
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock through employee equity incentive plans	1,631		1,631
Issuance of common stock through employee equity incentive plans, net of repurchases (in shares)		3,117
Issuance of common stock from ESPP purchase	18,070		18,070
Issuance of common stock from ESPP purchase (in shares)		1,456
Repurchase and retirement of common stock	(125,079)		(54,176)		(70,903)
Repurchase and retirement of common stock (in shares)		(5,176)
Stock-based compensation	89,198		89,198
Other comprehensive loss	(1,150)			(1,150)
Net loss	(265,048)				(265,048)
Stockholders' equity, ending balance at Oct. 31, 2020	(557,355)	$ 5	2,299,903	880	(2,858,143)
Stockholders' equity, ending balance (in shares) at Oct. 31, 2020		201,346
Stockholders' equity, beginning balance at Jul. 31, 2021	(1,012,041)	$ 5	2,615,317	(8)	(3,627,355)
Stockholders' equity, beginning balance (ASU 2020-06) at Jul. 31, 2021	$ (48,013)		(148,598)		100,585
Stockholders' equity, beginning balance (in shares) at Jul. 31, 2021	214,210	214,210
Increase (Decrease) in Stockholders' Equity [Roll Forward]
2026 Notes derivative liability reclassification	$ 698,213		698,213
Issuance of common stock through employee equity incentive plans	1,352		1,352
Issuance of common stock through employee equity incentive plans, net of repurchases (in shares)		2,809
Issuance of common stock from ESPP purchase	28,786		28,786
Issuance of common stock from ESPP purchase (in shares)		1,309
Repurchase and retirement of common stock	(58,570)		(14,852)		(43,718)
Repurchase and retirement of common stock (in shares)		(1,369)
Unwinding of 2023 Notes hedges	39,880		39,880
Unwinding of 2023 Notes warrants	(18,390)		(18,390)
Stock-based compensation	90,547		90,547
Other comprehensive loss	(651)			(651)
Net loss	(419,852)				(419,852)
Stockholders' equity, ending balance at Oct. 31, 2021	$ (698,739)	$ 5	$ 3,292,255	$ (659)	$ (3,990,340)
Stockholders' equity, ending balance (in shares) at Oct. 31, 2021	216,959	216,959