COMMITMENTS AND CONTINGENT LIABILITIES - FUTURE COMMITTED EXPENSES (Details) $ in Thousands	3 Months Ended
Dec. 31, 2025 USD ($)
Long-term Purchase Commitment [Line Items]
Current charges recoverable through BGSS	$ 190,700
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2026	311,770
2027	303,563
2028	181,101
2029	137,857
2030	129,837
Thereafter	790,454
ES
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2026	104,456
2027	63,887
2028	34,022
2029	16,317
2030	14,856
Thereafter	43,980
ES \| Natural gas purchases
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2026	72,429
2027	4,097
2028	0
2029	0
2030	0
Thereafter	0
ES \| Storage demand fees
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2026	10,351
2027	9,152
2028	6,382
2029	4,375
2030	4,375
Thereafter	5,788
ES \| Pipeline demand fees
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2026	21,676
2027	50,638
2028	27,640
2029	11,942
2030	10,481
Thereafter	38,192
Annual pipeline obligation to be paid over 10 year period	$ 4,000
Recorded unconditional purchase obligation term	10 years
NJNG
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2026	$ 207,314
2027	239,676
2028	147,079
2029	121,540
2030	114,981
Thereafter	746,474
NJNG \| Natural gas purchases
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2026	16,591
2027	0
2028	0
2029	0
2030	0
Thereafter	0
NJNG \| Storage demand fees
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2026	32,589
2027	35,494
2028	16,288
2029	5,982
2030	2,457
Thereafter	0
NJNG \| Pipeline demand fees
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2026	158,134
2027	204,182
2028	130,791
2029	115,558
2030	112,524
Thereafter	$ 746,474
Minimum \| ES
Long-term Purchase Commitment [Line Items]
Storage and pipeline capacity, contract term	1 year
Maximum \| ES
Long-term Purchase Commitment [Line Items]
Storage and pipeline capacity, contract term	10 years

Current Charges Recoverable Through Basic Gas Supply Service as shown for the reporting period

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Purchase Obligation, To Be Paid, After Year Four

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Recorded Unconditional Purchase Obligation Term

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Recorded Unconditional Purchase Obligation, To Be Paid Annual By Counterparty Over 10 Year Period

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- Definition

Storage and Pipeline Capacity, Term of Contract

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Amount of purchase arrangement to be paid in fourth fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3

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Amount of purchase arrangement to be paid in second fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of purchase arrangement to be paid in third fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of recorded unconditional purchase obligation to be paid in remainder of current fiscal year.

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