Balance Sheet Components - Schedule of Activity of Deferred Contract Acquisition Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Contract Acquisition Cost [Roll Forward]
Beginning balance	$ 26,150	$ 18,079	$ 10,135
Capitalization of contract acquisition costs	45,713	29,445	20,675
Amortization of deferred contract acquisition costs	(28,314)	(21,374)	(12,731)
Ending balance	43,549	26,150	18,079
Deferred contract acquisition costs				$ 19,537	$ 17,215	$ 12,125
Deferred contract acquisition costs, non-current				24,012	8,935	5,954
Total deferred contract acquisition costs	$ 26,150	$ 26,150	$ 18,079	$ 43,549	$ 26,150	$ 18,079