SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - NATURAL GAS IN STORAGE (Details) $ in Thousands	Jun. 30, 2023 USD ($) Bcf	Sep. 30, 2022 USD ($) Bcf
Inventory [Line Items]
Natural Gas in Storage, value | $	$ 155,077	$ 273,644
Natural Gas in Storage, Bcf | Bcf	41,500,000	39,800,000
Natural Gas Distribution
Inventory [Line Items]
Natural Gas in Storage, value | $	$ 118,776	$ 191,175
Natural Gas in Storage, Bcf | Bcf	21,700,000	29,000,000.0
Energy Services
Inventory [Line Items]
Natural Gas in Storage, value | $	$ 36,301	$ 82,469
Natural Gas in Storage, Bcf | Bcf	19,800,000	10,800,000