Net Income (Loss) Per Share (Details 1) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Apr. 30, 2020	Apr. 30, 2019
Numerator:
Net income (loss)	$ (31,038)	$ (19,944)	$ (14,991)	$ (8,581)	$ (1)	$ 6,309	$ (65,973)	$ (2,273)
Net income (loss) per share:
Basic (in dollars per share)	$ (0.37)			$ (0.11)			$ (0.80)	$ (0.03)
Diluted (in dollars per share)	$ (0.37)			$ (0.11)			$ (0.80)	$ (0.03)
Weighted average shares used in computing net income (loss) per share:
Basic (in shares)	83,024,291			81,606,088			82,701,267	81,252,993
Weighted average effect of dilutive stock options (in shares)	0			0			0	0
Weighted average effect of dilutive stock awards (in shares)	0			0			0	0
Diluted (in shares)	83,024,291			81,606,088			82,701,267	81,252,993