DERIVATIVE INSTRUMENTS - OFFSETTING OF ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Energy Services
Derivative assets:
Amounts Presented in Balance Sheets	$ 27,216	$ 30,683
Offsetting Derivative Instruments	(6,643)	(12,619)
Financial Collateral Received/Pledged	(460)	(200)
Net Amounts	20,113	17,864
Derivative liabilities:
Amounts Presented in Balance Sheets	30,627	57,747
Offsetting Derivative Instruments	(6,643)	(12,619)
Financial Collateral Received/Pledged	0	0
Net Amounts	23,984	45,128
Energy Services | Physical commodity contracts
Derivative assets:
Amounts Presented in Balance Sheets	7,226	10,233
Offsetting Derivative Instruments	(2,231)	(404)
Financial Collateral Received/Pledged	(460)	(200)
Net Amounts	4,535	9,629
Derivative liabilities:
Amounts Presented in Balance Sheets	26,215	30,612
Offsetting Derivative Instruments	(2,231)	(404)
Financial Collateral Received/Pledged	0	0
Net Amounts	23,984	30,208
Energy Services | Financial commodity contracts
Derivative assets:
Amounts Presented in Balance Sheets	19,990	20,432
Offsetting Derivative Instruments	(4,412)	(12,198)
Financial Collateral Received/Pledged	0	0
Net Amounts	15,578	8,234
Derivative liabilities:
Amounts Presented in Balance Sheets	4,412	27,118
Offsetting Derivative Instruments	(4,412)	(12,198)
Financial Collateral Received/Pledged	0	0
Net Amounts	0	14,920
Energy Services | Foreign currency contracts
Derivative assets:
Amounts Presented in Balance Sheets		18
Offsetting Derivative Instruments		(17)
Financial Collateral Received/Pledged		0
Net Amounts		1
Derivative liabilities:
Amounts Presented in Balance Sheets		17
Offsetting Derivative Instruments		(17)
Financial Collateral Received/Pledged		0
Net Amounts		0
Natural Gas Distribution
Derivative assets:
Amounts Presented in Balance Sheets	6,775	337
Offsetting Derivative Instruments	(189)	(85)
Financial Collateral Received/Pledged	0	0
Net Amounts	6,586	252
Derivative liabilities:
Amounts Presented in Balance Sheets	193	6,292
Offsetting Derivative Instruments	(189)	(85)
Financial Collateral Received/Pledged	0	0
Net Amounts	4	6,207
Natural Gas Distribution | Physical commodity contracts
Derivative assets:
Amounts Presented in Balance Sheets	61	252
Offsetting Derivative Instruments	(1)	0
Financial Collateral Received/Pledged	0	0
Net Amounts	60	252
Derivative liabilities:
Amounts Presented in Balance Sheets	5	11
Offsetting Derivative Instruments	(1)	0
Financial Collateral Received/Pledged	0	0
Net Amounts	4	11
Natural Gas Distribution | Financial commodity contracts
Derivative assets:
Amounts Presented in Balance Sheets	6,714	85
Offsetting Derivative Instruments	(188)	(85)
Financial Collateral Received/Pledged	0	0
Net Amounts	6,526	0
Derivative liabilities:
Amounts Presented in Balance Sheets	188	6,281
Offsetting Derivative Instruments	(188)	(85)
Financial Collateral Received/Pledged	0	0
Net Amounts	$ 0	$ 6,196