REGULATION - ADDITIONAL INFORMATION (Details) - USD ($) $ in Millions											9 Months Ended
	Jul. 26, 2024	Jun. 28, 2024	May 31, 2024	May 15, 2024	Apr. 30, 2024	Mar. 28, 2024	Mar. 20, 2024	Jan. 31, 2024	Dec. 01, 2023	Nov. 09, 2023	Jun. 30, 2024
Schedule of Regulatory Filings [Line Items]
Approved rate increase (decrease), amount										$ 76.9
NJNG
Schedule of Regulatory Filings [Line Items]
Approved rate increase (decrease), amount						$ 43.5
Base Rate Stipulation
Schedule of Regulatory Filings [Line Items]
Weighted average cost of capital											6.84%
Approved return on equity											9.60%
SAVEGREEN
Schedule of Regulatory Filings [Line Items]
Capital investments approved by the BPU									$ 245.1
Financing options									217.2
Operations and maintenance expense									$ 20.1
SAVEGREEN | NJNG
Schedule of Regulatory Filings [Line Items]
Annual recovery increase			$ 5.6
BPU | NJNG
Schedule of Regulatory Filings [Line Items]
Weighted average cost of capital								7.57%
Approved return on equity								10.42%
Approved rate increase (decrease), amount				$ 219.6		$ 5.3		$ 222.6
Annual recovery increase		$ 6.8
BPU | NJNG | Subsequent Event
Schedule of Regulatory Filings [Line Items]
Interim rate increase (decrease), amount	$ 41.2
RAC
Schedule of Regulatory Filings [Line Items]
Approved rate increase (decrease), amount							$ 2.4
NJCEP
Schedule of Regulatory Filings [Line Items]
Approved rate increase (decrease), amount							$ 5.5
BGSS | NJNG
Schedule of Regulatory Filings [Line Items]
Approved rate increase (decrease), amount			(31.0)		$ (38.6)
BGSS Balancing | NJNG
Schedule of Regulatory Filings [Line Items]
Approved rate increase (decrease), amount			40.3		(7.4)
CIP | NJNG
Schedule of Regulatory Filings [Line Items]
Approved rate increase (decrease), amount			$ (0.6)		$ 27.0