Balance Sheet Components - Schedule of Significant Changes in Unbilled Accounts Receivable (Details) - USD ($) $ in Thousands	6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Unbilled Account Receivable [Roll Forward]
Beginning balance	$ 2,622	$ 1,710
Amounts transferred to accounts receivable from unbilled accounts receivable presented at the beginning of the period	(2,622)	(1,710)
Additions through acquisition	0	321
Revenue recognized during the period in excess of invoices issued	3,046	2,309
Ending balance	$ 3,046	$ 2,630