Leases - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2023	Oct. 31, 2022	Oct. 31, 2023	Oct. 31, 2022
Lessee, Lease, Description [Line Items]
Operating leases, rent expense	$ 454	$ 466	$ 907	$ 934
Weighted average remaining lease term (in years)	5 years 2 months 19 days		5 years 2 months 19 days
Weighted average discount rate, percent	5.87%		5.87%
Corporate Headquarters
Lessee, Lease, Description [Line Items]
Operating leases, rent expense	$ 19	21	$ 38	42
Rockville, MD
Lessee, Lease, Description [Line Items]
Operating leases, rent expense	423	422	846	844
Milan Italy
Lessee, Lease, Description [Line Items]
Operating leases, rent expense	$ 13	$ 23	$ 26	$ 48