SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES- ASSET RETIREMENT OBLIGATIONS (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Estimated Accretion
2024	$ 3,114
2025	3,268
2026	3,429
2027	3,597
2028	3,781
Future accretion	17,189
NJNG
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at period beginning	49,874	$ 41,611
Accretion	2,693	2,052
Additions	155	161
Change in assumptions	4,089	7,339
Retirements	(1,526)	(1,289)
Balance at period ending	55,285	49,874
NJRCEV
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at period beginning	5,161	4,694
Accretion	213	186
Additions	1,334	281
Change in assumptions	0	0
Retirements	0	0
Balance at period ending	$ 6,708	$ 5,161