Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (31,038)	$ (8,581)	$ (65,973)	$ (2,273)
Foreign currency translation adjustments	(2,710)	(983)	(2,999)	(1,560)
Unrealized gains (losses) on available-for-sale securities	342	889	1,504	2,174
Tax benefit (expense) on unrealized gains (losses) on available-for-sale securities	(142)	(185)	(422)	(426)
Reclassification adjustment for realized gains (losses) included in net income (loss)	253	(111)	266	(384)
Total other comprehensive income (loss)	(2,257)	(390)	(1,651)	(196)
Comprehensive income (loss)	$ (33,295)	$ (8,971)	$ (67,624)	$ (2,469)