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Sale Leaseback Transaction, Net Proceeds, Financing Activities, Solar

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DEBT - LONG TERM DEBT (Details) - USD ($) $ in Thousands	3 Months Ended
DEBT - LONG TERM DEBT (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Nov. 07, 2024
Debt Instrument [Line Items]
Proceeds from sale leaseback transactions - natural gas meters	$ 11,714	$ 8,814
Proceeds from sale leaseback transactions - solar	12,567	24,394
NJR \| Unsecured Senior Notes 5.55% \| Senior Notes
Debt Instrument [Line Items]
Face amount			$ 100,000
Stated interest rate			5.55%
NJNG
Debt Instrument [Line Items]
Proceeds from sale leaseback transactions - natural gas meters	11,700	8,800
NJRCEV
Debt Instrument [Line Items]
Proceeds from sale leaseback transactions - solar	$ 12,600	$ 24,400