SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - NATURAL GAS IN STORAGE (Details) $ in Thousands	Jun. 30, 2022 USD ($) Bcf	Sep. 30, 2021 USD ($) Bcf
Inventory [Line Items]
Natural Gas in Storage, value | $	$ 203,438	$ 193,606
Natural Gas in Storage, Bcf | Bcf	30,200,000	46,400,000
Natural Gas Distribution
Inventory [Line Items]
Natural Gas in Storage, value | $	$ 119,961	$ 115,824
Natural Gas in Storage, Bcf | Bcf	18,600,000	27,600,000
Energy Services
Inventory [Line Items]
Natural Gas in Storage, value | $	$ 83,477	$ 77,782
Natural Gas in Storage, Bcf | Bcf	11,600,000	18,800,000