OTHER ASSETS: - Additional Information (Details) - USD ($)	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Deferred purchase price	$ 0	$ 5,636,000
Depreciation	537,000	606,000
Operating Lease, Right-of-Use Asset	109,000
Property, Plant and Equipment
Depreciation	20,000	$ 17,000
Right of use assets
Operating Lease, Right-of-Use Asset	109,000
Amortization of leased cost	$ 104,000