Accrued Expenses and Deferred Revenue - Summary of Accrued Expenses (Detail) - USD ($) $ in Thousands	Apr. 30, 2022	Apr. 30, 2021
Accrued taxes other than income	$ 7,008	$ 12,210
Accrued other	3,956	3,451
Accrued employee benefits	3,705	4,780
Accrued distributor incentives	2,917	2,414
Accrued professional fees	1,997	2,804
Current portion of operating lease obligation	1,495	1,309
Accrued rebates and promotions	$ 1,243	$ 2,174
Operating Lease Liability Current Statement Of Financial Position [Extensible List]	Total accrued expenses and deferred revenue	Total accrued expenses and deferred revenue
Current portion of finance lease obligation	$ 1,158	$ 1,087
Finance Lease Liability Current Statement Of Financial Position [Extensible List]	Total accrued expenses and deferred revenue	Total accrued expenses and deferred revenue
Deferred revenue	$ 3	$ 2,907
Total accrued expenses and deferred revenue	$ 23,482	$ 33,136