SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - SOFTWARE COSTS (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2022
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Capitalized software costs	$ 6,649		$ 6,120
Software amortization	114	$ 113
Operation and maintenance
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Software costs	3,753	2,523
Depreciation and amortization
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Software costs	871	$ 299
Utility plant, at cost
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Software costs	46,066		40,437
Construction work in progress | Regulated
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Software costs	22,619		14,381
Nonutility plant and equipment, at cost
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Software costs	344		344
Accumulated depreciation and amortization, utility plant
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Accumulated depreciation and amortization	(4,229)		(3,361)
Accumulated depreciation and amortization, nonutility plant and equipment
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Accumulated depreciation and amortization	$ (28)		$ (25)