DERIVATIVE INSTRUMENTS - VOLUME (Details) - Bcf	9 Months Ended	12 Months Ended
	Jun. 30, 2022	Sep. 30, 2021
Natural Gas Distribution | Long | Futures
Derivative [Line Items]
Notional amount	27.3	22.2
Natural Gas Distribution | Long | Physical Commodity
Derivative [Line Items]
Notional amount	8.1	7.6
Energy Services | Long | Physical Commodity
Derivative [Line Items]
Notional amount	(0.4)	0.6
Energy Services | Short | Futures
Derivative [Line Items]
Notional amount	(5.1)	(13.4)
Energy Services | Short | Swaps
Derivative [Line Items]
Notional amount	(0.1)	(0.3)