REVENUES - Additional Information (Details)	3 Months Ended		6 Months Ended
	Oct. 31, 2020 a customer	Oct. 31, 2019 customer	Oct. 31, 2020 a customer	Oct. 31, 2019 customer
Property, Plant and Equipment [Line Items]
Surface areas of land held | a	6,000		6,000
Minerals and mineral rights
Property, Plant and Equipment [Line Items]
Surface areas of land held | a	55,000		55,000
Land sale revenues
Property, Plant and Equipment [Line Items]
Number of customers | customer	4	3	4	3
Home sale revenues
Property, Plant and Equipment [Line Items]
Number of customers | customer	1