OTHER REVENUES (Details Textual)		3 Months Ended
	Sep. 07, 2018	Jul. 31, 2018 USD ($) a	Jul. 31, 2017 USD ($)
Pre Tax Gain Included Other Revenues		$ 0	$ 1,318,000
Operating Leases, Income Statement, Lease Revenue		57,000
Deferred Revenue, Leases, Net		$ 19,000
Area of Land | a		55,000
Subsequent Event [Member]
Royalty InterestPercentage	1.00%
Lessor, Operating Lease, Description	If lessee or any of its affiliates provides any consideration to obtain, enter into, option, extend or renew an interest in any minerals or mineral rights within Sandoval County, Bernalillo County, Santa Fe County or Valencia County in New Mexico at any time from September 2017 through September 2020, lessee shall pay the Company an amount equal to the amount of such consideration paid per acre multiplied by 54,793.24.