Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Adoption of Accounting Standards Update ("ASU") 2018-02	Common stock Common stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated other comprehensive income (loss) Adoption of Accounting Standards Update ("ASU") 2018-02	Retained Earnings	Retained Earnings Adoption of Accounting Standards Update ("ASU") 2018-02
Beginning balance (in shares) at Jul. 31, 2019			82,140,883
Beginning balance at Jul. 31, 2019	$ 1,574,201	$ 0	$ 8	$ 1,391,904	$ (7,758)	$ (107)	$ 190,047	$ 107
Net loss	(14,991)						(14,991)
Issuance of common stock upon exercise of stock options (in shares)			21,698
Issuance of common stock upon exercise of stock options	368			368
Issuance of common stock upon vesting of Restricted Stock Units (RSU) (in shares)			411,825
Issuance of common stock upon vesting of Restricted Stock Units (“RSUs”)	0
Stock-based compensation	24,765			24,765
Foreign currency translation adjustment	133				133
Unrealized gain (loss) on available-for-sale securities, net of tax	1,003				1,003
Reclassification adjustment for realized gain (loss) on available-for-sale securities, included in net income (loss)	46				46
Ending balance (in shares) at Oct. 31, 2019			82,574,406
Ending balance at Oct. 31, 2019	1,585,525		$ 8	1,417,037	(6,683)		175,163
Beginning balance (in shares) at Jul. 31, 2020			83,461,925
Beginning balance at Jul. 31, 2020	1,656,768		$ 8	1,499,050	(5,246)		162,956
Net loss	$ (20,190)						(20,190)
Issuance of common stock upon exercise of stock options (in shares)	39,169		39,169
Issuance of common stock upon exercise of stock options	$ 1,716			1,716
Issuance of common stock upon vesting of Restricted Stock Units (RSU) (in shares)			339,759
Issuance of common stock upon vesting of Restricted Stock Units (“RSUs”)	0
Stock-based compensation	28,394			28,394
Repurchase and retirement of common stock (in shares)			(48,997)
Repurchase and retirement of common stock	(5,000)						(5,000)
Foreign currency translation adjustment	(694)				(694)
Unrealized gain (loss) on available-for-sale securities, net of tax	(1,480)				(1,480)
Reclassification adjustment for realized gain (loss) on available-for-sale securities, included in net income (loss)	347				347
Ending balance (in shares) at Oct. 31, 2020			83,791,856
Ending balance at Oct. 31, 2020	$ 1,659,861		$ 8	$ 1,529,160	$ (7,073)		$ 137,766