Net Loss Per Share Attributable to Ordinary Shareholders - Schedule of Computation of Basic and Diluted Net Loss Per Share Attributable to Ordinary Shareholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Numerator:
Net loss	$ (29,158)	$ (49,973)	$ (48,159)	$ (91,742)
Denominator:
Weighted-average shares used in computing net loss per share attributable to ordinary shareholders, basic and diluted (in shares)	86,373,166	77,772,406	85,275,474	76,202,865
Net loss per share attributable to ordinary shareholders, basic and diluted (in dollars per share)	$ (0.34)	$ (0.64)	$ (0.56)	$ (1.20)