DERIVATIVE INSTRUMENTS - INCOME STATEMENT RELATED DISCLOSURES (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (losses) gains recognized in income on derivatives	$ 50,979	$ 62,844
Energy Services | Physical commodity contracts | Operating revenues
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (losses) gains recognized in income on derivatives	10,038	150
Energy Services | Physical commodity contracts | Natural gas purchases
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (losses) gains recognized in income on derivatives	(670)	1,505
Energy Services | Financial commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (losses) gains recognized in income on derivatives	41,611	61,189
Natural Gas Distribution
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (losses) gains recognized in income on derivatives	(59,694)	(12,951)
Natural Gas Distribution | Physical commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (losses) gains recognized in income on derivatives	(28,031)	1,696
Natural Gas Distribution | Financial commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (losses) gains recognized in income on derivatives	$ (31,663)	$ (14,647)