Leases (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Jun. 30, 2020	Jul. 31, 2020	Apr. 30, 2022	Apr. 30, 2021	Apr. 01, 2021	Jun. 01, 2020	May 01, 2020	Mar. 30, 2020
Lessee, Lease, Description [Line Items]
Operating leases, rent expense			$ 1,900	$ 1,300
Renewal term								6 months
Operating lease right-of-use assets, net			8,230	8,521			$ 8,521
Operating lease, liability			9,466		$ 3,300
Gain on termination of operating lease			$ 0	75
Weighted average remaining lease term			6 years 8 months 12 days
Weighted average discount rate			5.73%
Corporate Headquarters
Lessee, Lease, Description [Line Items]
Operating leases, rent expense			$ 88	91
Rockville, MD
Lessee, Lease, Description [Line Items]
Operating leases, rent expense			1,700	1,200
Operating lease right-of-use assets, net		$ 118				$ 3,800
Operating lease, liability		125
Operating lease incremental rent expense		$ 8
Rockville, MD New Location
Lessee, Lease, Description [Line Items]
Operating leases, rent expense			0	43
Operating lease right-of-use assets, net	$ 850
Operating lease, liability	926
Gain on termination of operating lease	$ 76
Milan Italy
Lessee, Lease, Description [Line Items]
Operating leases, rent expense			$ 81	$ 0
Operating lease right-of-use assets, net								$ 205
Operating lease, liability								$ 205