DERIVATIVE INSTRUMENTS - OFFSETTING OF ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Sep. 30, 2025
ES
Asset Derivatives
Fair Value	$ 11,171	$ 14,453
Amounts Offset	(5,935)	(4,149)
Collateral Received/Pledged	(1,112)	(3,951)
Net Value	4,124	6,353
Liability Derivatives
Fair Value	13,353	11,897
Amounts Offset	(5,935)	(4,149)
Collateral Received/Pledged	(2,214)	(2,022)
Net Value	5,204	5,726
ES \| Physical commodity contracts
Asset Derivatives
Fair Value	4,049	5,021
Amounts Offset	(1,806)	(2,061)
Collateral Received/Pledged	0	0
Net Value	2,243	2,960
Liability Derivatives
Fair Value	9,224	9,809
Amounts Offset	(1,806)	(2,061)
Collateral Received/Pledged	(2,214)	(2,022)
Net Value	5,204	5,726
ES \| Financial commodity contracts
Asset Derivatives
Fair Value	7,122	9,432
Amounts Offset	(4,129)	(2,088)
Collateral Received/Pledged	(1,112)	(3,951)
Net Value	1,881	3,393
Liability Derivatives
Fair Value	4,129	2,088
Amounts Offset	(4,129)	(2,088)
Collateral Received/Pledged	0	0
Net Value	0	0
NJNG
Asset Derivatives
Fair Value	80	380
Amounts Offset	0	(5)
Collateral Received/Pledged	0	0
Net Value	80	375
Liability Derivatives
Fair Value	31	6
Amounts Offset	0	(5)
Collateral Received/Pledged	(31)	0
Net Value	0	1
NJNG \| Physical commodity contracts
Asset Derivatives
Fair Value	80	30
Amounts Offset	0	(1)
Collateral Received/Pledged	0	0
Net Value	80	29
Liability Derivatives
Fair Value	0	2
Amounts Offset	0	(1)
Collateral Received/Pledged	0	0
Net Value	0	1
NJNG \| Financial commodity contracts
Asset Derivatives
Fair Value	0	350
Amounts Offset	0	(4)
Collateral Received/Pledged	0	0
Net Value	0	346
Liability Derivatives
Fair Value	31	4
Amounts Offset	0	(4)
Collateral Received/Pledged	(31)	0
Net Value	$ 0	$ 0

Collateral or equivalent pledged or received against derivative assets

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- Definition

Collateral or equivalent pledged or received against derivative liabilities.

+ References

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- Definition

Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

+ References

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, after effect of master netting arrangement and deduction of obligation to return financial collateral not offset and financial instrument subject to master netting arrangement not offset, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and contract can be net settled by means outside contract or delivery of asset. Includes derivative not subject to master netting arrangement or similar agreement.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Fair value, after effect of master netting arrangement and deduction of obligation to return financial collateral not offset and financial instrument subject to master netting arrangement not offset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and contract can be net settled by means outside contract or delivery of asset. Includes derivative not subject to master netting arrangement or similar agreement.

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Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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