Presentation and Summary of Significant Accounting Policies - Disaggregated Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 127,553	$ 111,408	$ 115,466
Domestic
Disaggregation of Revenue [Line Items]
Total revenues	107,099	94,676
International
Disaggregation of Revenue [Line Items]
Total revenues	$ 20,454	$ 16,732