Balance Sheet Components - Schedule of Significant Changes in Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Movement in Deferred Revenue [Roll Forward]
Beginning balance	$ 170,666	$ 102,561	$ 54,152
Additions through acquisition	6,192	0	859
Increases due to invoices issued, excluding amounts recognized as revenue during the period	242,136	163,963	96,944
Revenue recognized that was included in deferred revenue balance at beginning of period	(159,292)	(95,858)	(49,394)
Ending balance	$ 259,702	$ 170,666	$ 102,561