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Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

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Amount of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property.

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The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

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ACQUISITIONS AND DISPOSITIONS - DISPOSITIONS (Details) $ in Thousands				12 Months Ended
	Feb. 07, 2019 USD ($)	Jun. 01, 2018 USD ($) MW	Feb. 28, 2018 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of businesses, net				$ 0	$ 645	$ 4,663
Proceeds from sale of businesses, net of closing costs				$ 0	$ 205,745	$ 27,916
Clean Energy Ventures
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Wind farm total capacity (in MW) \| MW		9.7
Disposal group consideration	$ 208,600	$ 18,500
Proceeds from sale of business		$ 951
Gain on sale of businesses, net	$ 645
Clean Energy Ventures \| Natural Gas
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Derivative gain			$ 14,600
Issued And Outstanding Shares Of NRJ Retail Services
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of business			3,700
Proceeds from sale of businesses, net of closing costs			$ 9,500