Revenue - Deferred Revenue Balance (Details) - USD ($) $ in Thousands		Jul. 31, 2021	Apr. 30, 2021	Jul. 31, 2020	Apr. 30, 2020
Revenue from Contract with Customer [Abstract]
Deferred revenue, current	[1]	$ 98,217	$ 72,263
Deferred revenue, non-current		1,680	2,964
Total deferred revenue		$ 99,897	$ 75,227	$ 107,244	$ 60,295

[1] Including amounts from a related party of $24,637 and $7,697 as of July 31, 2021 and April 30, 2021, respectively.