SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, CAPITALIZED AND DEFERRED INTEREST (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
AFUDC:
SBC interest rate	2.05%	2.54%	2.65%
Deferred interest	$ 54	$ 61	$ 586
Seven-Year Treasury Rate
AFUDC:
Debt instrument, term	7 years
Basis spread on Treasury rate	0.60%
NJNG
AFUDC:
Debt	$ 5,009	2,472	1,057
Equity	4,375	3,825	1,562
Total	$ 9,384	$ 6,297	$ 2,619
Weighted average interest rate	5.06%	4.63%	3.30%