DEBT, SALE-LEASEBACKS (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Debt Instrument [Line Items]
Proceeds from sale-leaseback transaction	$ 7,107	$ 7,216	$ 7,576
NJNG
Debt Instrument [Line Items]
Sale leaseback transaction, lease term	25 years 6 months
Sale leaseback transaction, lease renewal term	5 years
Sale leaseback transaction, maximum lease renewal term (as a percent)	4
Proceeds from sale-leaseback transaction	$ 7,100	7,200	7,600
Sale leaseback transaction, other payments required	$ 1,900	$ 768	$ 956