DEBT - LONG TERM DEBT (Details) - USD ($)	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Sep. 28, 2023
Debt Instrument [Line Items]
Proceeds from sale leaseback transactions - natural gas meters	$ 8,814,000	$ 8,441,000
Proceeds from sale leaseback transactions - solar	24,394,000	33,150,000
CEV
Debt Instrument [Line Items]
Proceeds from sale leaseback transactions - solar	24,400,000	33,200,000
NJNG
Debt Instrument [Line Items]
Proceeds from sale leaseback transactions - natural gas meters	$ 8,800,000	$ 8,400,000
NJNG | Senior Notes
Debt Instrument [Line Items]
Face amount			$ 100,000,000
NJNG | Senior Notes | Unsecured Senior Notes 5.56%
Debt Instrument [Line Items]
Face amount			$ 50,000,000
Stated interest rate			5.56%
NJNG | Senior Notes | Unsecured Senior Notes 5.85%
Debt Instrument [Line Items]
Face amount			$ 50,000,000
Stated interest rate			5.85%