DERIVATIVE INSTRUMENTS - OFFSETTING OF ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Sep. 30, 2021
Energy Services
Derivative assets:
Amounts Presented in Balance Sheets	$ 26,662	$ 36,572
Offsetting Derivative Instruments	(11,788)	(34,191)
Financial Collateral Received/Pledged	(200)	19,832
Net Amounts	14,674	22,213
Derivative liabilities:
Amounts Presented in Balance Sheets	69,948	100,613
Offsetting Derivative Instruments	(11,788)	(34,191)
Financial Collateral Received/Pledged	0	0
Net Amounts	58,160	66,422
Energy Services | Physical commodity contracts
Derivative assets:
Amounts Presented in Balance Sheets	3,535	3,151
Offsetting Derivative Instruments	(1,223)	(894)
Financial Collateral Received/Pledged	(200)	(700)
Net Amounts	2,112	1,557
Derivative liabilities:
Amounts Presented in Balance Sheets	40,608	37,829
Offsetting Derivative Instruments	(1,223)	(894)
Financial Collateral Received/Pledged	0	0
Net Amounts	39,385	36,935
Energy Services | Financial commodity contracts
Derivative assets:
Amounts Presented in Balance Sheets	23,120	33,294
Offsetting Derivative Instruments	(10,562)	(33,294)
Financial Collateral Received/Pledged	0	20,532
Net Amounts	12,558	20,532
Derivative liabilities:
Amounts Presented in Balance Sheets	29,337	62,781
Offsetting Derivative Instruments	(10,562)	(33,294)
Financial Collateral Received/Pledged	0	0
Net Amounts	18,775	29,487
Energy Services | Foreign currency contracts
Derivative assets:
Amounts Presented in Balance Sheets	7	127
Offsetting Derivative Instruments	(3)	(3)
Financial Collateral Received/Pledged	0	0
Net Amounts	4	124
Derivative liabilities:
Amounts Presented in Balance Sheets	3	3
Offsetting Derivative Instruments	(3)	(3)
Financial Collateral Received/Pledged	0	0
Net Amounts	0	0
Natural Gas Distribution
Derivative assets:
Amounts Presented in Balance Sheets	88	2,082
Offsetting Derivative Instruments	(71)	(21)
Financial Collateral Received/Pledged	0	0
Net Amounts	17	2,061
Derivative liabilities:
Amounts Presented in Balance Sheets	10,223	29
Offsetting Derivative Instruments	(71)	(21)
Financial Collateral Received/Pledged	0	0
Net Amounts	10,152	8
Natural Gas Distribution | Physical commodity contracts
Derivative assets:
Amounts Presented in Balance Sheets	18	36
Offsetting Derivative Instruments	(1)	(8)
Financial Collateral Received/Pledged	0	0
Net Amounts	17	28
Derivative liabilities:
Amounts Presented in Balance Sheets	14	16
Offsetting Derivative Instruments	(1)	(8)
Financial Collateral Received/Pledged	0	0
Net Amounts	13	8
Natural Gas Distribution | Financial commodity contracts
Derivative assets:
Amounts Presented in Balance Sheets	70	2,046
Offsetting Derivative Instruments	(70)	(13)
Financial Collateral Received/Pledged	0	0
Net Amounts	0	2,033
Derivative liabilities:
Amounts Presented in Balance Sheets	10,209	13
Offsetting Derivative Instruments	(70)	(13)
Financial Collateral Received/Pledged	0	0
Net Amounts	$ 10,139	$ 0