Leases - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2024	Apr. 30, 2023
Lessee, Lease, Description [Line Items]
Operating leases, rent expense	$ 1,800	$ 1,900
Weighted average remaining lease term (in years)	4 years 8 months 12 days	5 years 8 months 12 days
Weighted average discount rate, percent	5.88%	5.82%
Corporate Headquarters
Lessee, Lease, Description [Line Items]
Operating leases, rent expense	$ 77	$ 83
Rockville, MD
Lessee, Lease, Description [Line Items]
Operating leases, rent expense	1,700	1,700
Milan, Italy
Lessee, Lease, Description [Line Items]
Operating leases, rent expense	$ 50	$ 98