XML 49 R39.htm IDEA: XBRL DOCUMENT v3.21.2
REVENUES - Additional Information (Details)
$ in Thousands
 3 Months Ended
Jul. 31, 2021
USD ($)
customer
Jul. 31, 2020
USD ($)
customer
Property, Plant and Equipment [Line Items]    
Revenues $ 10,507 $ 4,206
Customer outstanding receivables 0 0
Public reimbursement 309 175
Royalties 135 11
Customer A    
Property, Plant and Equipment [Line Items]    
Revenues 4,200,000 1,900,000
Customer B    
Property, Plant and Equipment [Line Items]    
Revenues $ 1,700,000 1,000,000
Customer C    
Property, Plant and Equipment [Line Items]    
Revenues   $ 433,000
Land sale revenues    
Property, Plant and Equipment [Line Items]    
Number of customers | customer 3 4