COMMITMENTS AND CONTINGENCIES (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Kaupulehu Developments
Commitments and contingencies
Fees to be paid to Nearco	10.40%
Percentage of Increment II receipts to be paid to external real estate counsel for services provided in the negotiation and closing of the Increment II transaction	1.50%
Oil pipeline release [Member]
Commitments and contingencies
Probable environmental remediation costs	$ 2,200,000
Percentage of working interest	58.00%
Insurance deductible	$ 80,000
Accrual for environmental remediation costs	$ 0
Gas leak [Member]
Commitments and contingencies
Percentage of working interest	50.00%
Accrual for environmental remediation costs	$ 200,000
Minimum | Gas leak [Member]
Commitments and contingencies
Probable environmental remediation costs	400,000
Maximum | Gas leak [Member]
Commitments and contingencies
Probable environmental remediation costs	800,000
Lease Agreements [Member]
Commitments and contingencies
Rental expense	404,000	$ 408,000
Minimum rental payments
2017	261,000
2018	138,000
2019	118,000
2020	118,000
2021	118,000
Thereafter through 2026	130,000
Total	$ 883,000