XML 67 R40.htm IDEA: XBRL DOCUMENT v3.21.2
Inventories - Summary of Inventories (Detail) - USD ($)
$ in Thousands
Apr. 30, 2021
Apr. 30, 2020
Inventory Disclosure [Abstract]    
Finished goods $ 2,988 $ 2,455
Work-in-process 1,832 1,921
Materials and components 11,697 10,954
Total inventories $ 16,517 $ 15,330