COMMITMENTS AND CONTINGENT LIABILITIES - SCHEDULE OF FUTURE COMMITTED EXPENSES (Details) $ in Thousands	9 Months Ended
Jun. 30, 2023 USD ($)
Long-term Purchase Commitment [Line Items]
Current charges recoverable through BGSS	$ 195,500
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2023	85,578
2024	301,549
2025	242,437
2026	185,978
2027	166,206
Thereafter	1,136,451
Energy Services
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2023	35,110
2024	103,016
2025	57,394
2026	41,271
2027	32,547
Thereafter	52,453
Energy Services \| Natural gas purchases
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2023	13,851
2024	38,526
2025	2,671
2026	0
2027	0
Thereafter	0
Energy Services \| Storage demand fees
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2023	5,561
2024	16,874
2025	8,098
2026	6,010
2027	4,878
Thereafter	10,285
Energy Services \| Pipeline demand fees
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2023	15,698
2024	47,616
2025	46,625
2026	35,261
2027	27,669
Thereafter	42,168
Annual pipeline obligation to be paid over 10 year period	4,000
Natural Gas Distribution
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2023	50,468
2024	198,533
2025	185,043
2026	144,707
2027	133,659
Thereafter	1,083,998
Natural Gas Distribution \| Natural gas purchases
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2023	4,519
2024	371
2025	0
2026	0
2027	0
Thereafter	0
Natural Gas Distribution \| Storage demand fees
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2023	11,238
2024	42,049
2025	30,048
2026	14,353
2027	9,541
Thereafter	4,773
Natural Gas Distribution \| Pipeline demand fees
Natural Gas Purchases and Future Demand Fees, Next Five Fiscal Years
2023	34,711
2024	156,113
2025	154,995
2026	130,354
2027	124,118
Thereafter	$ 1,079,225
Minimum \| Energy Services
Long-term Purchase Commitment [Line Items]
Storage and pipeline capacity, contract term	1 year
Maximum \| Energy Services
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, To Be Paid Annual By Counterparty Over 10 Year Period

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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).

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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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